Naomi's car can go a maximum
of 125 miles on 1 tank of gas.
She has already driven 5 miles
on her current tank. If it takes
her 30 miles roundtrip to get
to work, how many times can
she drive to work before she
has to fill
up
the tank?

Answer:

See below for answers and explanations

Step-by-step explanation:

Problem 1

[tex]u\cdot v=\langle4,-7\rangle\cdot\langle-6,9\rangle=(4*-6)+(-7*9)=-24-63=-87[/tex], so A is correct. Remember to multiply the horizontal components with each other and then add that to the product of the vertical components to get the dot product.

Problem 2

Two vectors are orthogonal if their dot product is 0, which also means that they must be perpendicular to each other, so we can check this:

[tex]u\cdot v=(6*-24)+(-9*36)=-144-324=-468[/tex]

Since the dot product of the two vectors is 0, they aren't orthogonal. Therefore, they are parallel since [tex]v=4u[/tex], making A the best choice.

Problem 3

Recall that the angle between two vectors is [tex]\theta=cos^{-1}(\frac{u\cdot v}{||u||*||v||})[/tex] where [tex]u\cdot v[/tex] is the dot product of vectors [tex]u[/tex] and [tex]v[/tex] while [tex]||u||[/tex] and [tex]||v||[/tex] are the magnitudes of vectors [tex]u[/tex] and [tex]v[/tex] respectively. If we let [tex]F_1=u[/tex] and [tex]F_2=v[/tex], we can then continue on:

[tex]u\cdot v=(190*128)+(160*-121)=24320+(-19360)=4960[/tex]

[tex]||u||=\sqrt{190^2+160^2}=\sqrt{61700}=10\sqrt{617}[/tex]

[tex]||v||=\sqrt{128^2+(-121)^2}=\sqrt{31025}=5\sqrt{1241}[/tex]

[tex]\theta=cos^{-1}(\frac{u\cdot v}{||u||*||v||})\\\\\theta=cos^{-1}(\frac{4960}{10\sqrt{617}*5\sqrt{1241}})\\\\\theta\approx83.49^\circ\approx83^\circ[/tex]

Therefore, B is the correct answer

Problem 4

We observe that [tex]u=\langle-8,-9\rangle[/tex] and [tex]v=\langle3,7\rangle[/tex], so [tex]-3(u\cdot v)=-3[(-8*3)+(-9*7)]=-3[-24+(-63)]=-3(-87)=261[/tex]. This means that B is the correct answer.

Problem 5

Recall that the projection of a vector [tex]u[/tex] onto [tex]v[/tex] is [tex]proj_vu=(\frac{u\cdot v}{||v||^2})v[/tex], thus:

[tex]proj_vu=(\frac{u\cdot v}{||v||^2})v\\\\proj_vu=(\frac{(-10*4)+(-3*8)}{\sqrt{4^2+8^2}^2})\langle4,8\rangle\\\\proj_vu=(\frac{-40+(-24)}{\sqrt{80}^2})\langle4,8\rangle\\\\proj_vu=(\frac{-64}{80})\langle4,8\rangle\\\\proj_vu=(-\frac{4}{5})\langle4,8\rangle\\\\proj_vu=\langle-\frac{16}{5},-\frac{32}{5}\rangle[/tex]

Therefore, D is the correct answer

Answer: 592330

Step-by-step explanation:

Answer:

Step-by-step explanation:

2x + 3y = 2

x = 2 - 3y /2

x + y = 0

substitute the value of x

[tex]\frac{2 \\- 3y}{2}[/tex] + y = 0

2 - 3y + 2y = 0

2 = y

again,substitute the value of y

x = 2 - 3y / 2

=2 - 3*2 / 2

=2 - 6 / 2

=-2

Answer:

x = 2, y = -2

Step-by-step explanation:

This is an alternate way. You can also solve simultaneous equations using matrices. First, rewrite the simultaneous equations in matrix form.

[tex]\displaystyle \large{\left[\begin{array}{ccc}2&3\\1&1\end{array}\right] \left[\begin{array}{ccc}x\\y\end{array}\right] =\left[\begin{array}{ccc}2\\0\end{array}\right]}[/tex]

Let:

[tex]\displaystyle \large{A= \left[\begin{array}{ccc}2&3\\1&1\end{array}\right]}\\\displaystyle \large{X = \left[\begin{array}{ccc}x\\y\end{array}\right]}\\\displaystyle \large{B =\left[\begin{array}{ccc}2\\0\end{array}\right]}[/tex]

So now we have [tex]\displaystyle \large{AX = B}[/tex] and we have to solve for X which:

[tex]\displaystyle \large{A^{-1}AX = A^{-1}B}\\\displaystyle \large{X = A^{-1} B}[/tex]

Where:

[tex]\displaystyle \large{A^{-1}=\frac{1}{ad-bc}\left[\begin{array}{ccc}d&-b\\-c&a\end{array}\right]}[/tex]

**ad-bc is determinant of 2*2 matrices and shortened as det(var) or |var|**

Therefore, from A:

Find detA:

[tex]\displaystyle \large{\det A = |A| = ad-bc = 2(1)-3(1) = 2-3 = -1}[/tex]

Therefore, detA = -1. Hence:

[tex]\displaystyle \large{A^{-1}=-1\left[\begin{array}{ccc}1&-3\\-1&2\end{array}\right]}[/tex]

And [tex]\displaystyle \large{X = A^{-1}B}[/tex]:

[tex]\displaystyle \large{X = -1\left[\begin{array}{ccc}1&-3\\-1&2\end{array}\right] \left[\begin{array}{ccc}2\\0\end{array}\right] }[/tex]

Evaluate the matrices:

[tex]\displaystyle \large{X = -1\left[\begin{array}{ccc}1 \cdot 2-3 \cdot 0\\-1 \cdot 2+2\cdot 0\end{array}\right] }\\\displaystyle \large{X = -1\left[\begin{array}{ccc}2-0\\-2+0\end{array}\right] }\\\displaystyle \large{X = -1\left[\begin{array}{ccc}2\\-2\end{array}\right] }\\\displaystyle \large{X = \left[\begin{array}{ccc}-2\\2\end{array}\right] }\\\displaystyle \large{\left[\begin{array}{ccc}x\\y\end{array}\right] = \left[\begin{array}{ccc}-2\\2\end{array}\right] }[/tex]

Therefore, x = -2 and y = 2.

The vertical distance from the ground to your eye is 10.9 feet and the height of the tree is 20.5 feet.

Pythagoras theorem is used to show the relationship between the sides of a right angled triangle. It is given by:

Hypotenuse² = Adjacent² + Opposite²

From the diagram, let d represent the horizontal distance, hence:

d² = 9.2² + 4.8²

d = 10.9 feet

Let h represent the height of the tree, hence:

h / 10.9 = 10.9 / 5.8

h = 20.5 feet

The vertical distance from the ground to your eye is 10.9 feet and the height of the tree is 20.5 feet.

Find out more on Pythagoras theorem at: https://brainly.com/question/343682

Answer:

Step-by-step explanation:

first of all you need to do is make a lemonade stand and make the lemonade taiste good then you can sell it for 15 dollars which is a good price to get you started with your life

Answer:

1. (4,5)  2. D  3. J  4.D  5. 64.8 oz

Step-by-step explanation:

math

Answer:

3.

Step-by-step explanation:

Since angle DBC and DBA are supplementary (they add up to a straight angle-180 degrees) we can subtract 121 from 180 and find out the answer of  angle DBA.

Answer:

3.............

................

Answer:

Mari watch died of eating Boba drinks

Answer:

17

Step-by-step explanation:

Seeing that traingle ABC is = to triangle DEF.

It means that the angles are equal too.

So you would equate them to each other.

Hence 5X+2=87

5X=87-2

5X=85 (divide by 5)

X=17

Hope that helps :)

Answer:

Angles in a triangle adds to 180

Step-by-step explanation:

Hope this helps!

Answer:

40 minutes later

Step-by-step explanation:

6:15 + 40 minutes = 6:55

Answer:

(B) 10

Step-by-step explanation:

x = 15

y = 3

---------------------------------

9(5) - x / y =

The value of the given expression [tex]\dfrac{9(5)-x}{y}[/tex] is 10 when x = 15 and y = 3. So, the correct answer is (b) 10.

An expression is a combination of numbers, variables, mathematical operations, and many more.

To obtain the value of the given expression, the values of x and y will be inserted in the expression and the concepts of PEMDAS will be used.

Let's assume that the given expression is as follows:

[tex]z = \dfrac{9(5)-x}{y}[/tex]

Substitute x = 15 and y = 3 in the given expression:

[tex]z = \dfrac{9(5)-x}{y}\\z = \dfrac{9(5)-15}{3}\\z = \dfrac{45-15}{3}\\z = \dfrac{30}{3}\\z = 10[/tex]

Therefore, option (d) is correct, i.e., for x = 15 and y = 3, the value of the given expression is 10.

Learn more about Expressions here:

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Answer:

Step-by-step explanation:

Distance = d

d² = [1 - (-3)]² + [y - (-6)]²

5² = 16 + (y + 6)²

25 = 16 + (y + 6)²

(y + 6)² = 25 - 16 = 9

y + 6 = ±3

y = -6 ±3

so

y = -3 or -9

Consider the given quadratic equation that we have :

[tex]{:\implies \quad \sf -5x^{2}+5=-2x}[/tex]

Multiplying both sides by -1 will yield ;

[tex]{:\implies \quad \sf 5x^{2}-5=2x}[/tex]

Write the above quadratic equation in the form of standard quadratic equation ax² + bx + c = 0 ,

[tex]{:\implies \quad \sf 5x^{2}-2x-5=0}[/tex]

Now , comparing this with the standard form of quadratic equation we will get a = 5 , b = -2 , c = -5 . So now , Discriminant (D) = (-2)² - 4 × 5 × -5 = 4 + 100 = 104

Now , by the quadratic formula ;

[tex]{:\implies \quad \sf x=\dfrac{-(-2)\pm \sqrt{104}}{2\times 5}}[/tex]

[tex]{:\implies \quad \sf x=\dfrac{2\pm 2\sqrt{26}}{2\times 5}}[/tex]

[tex]{:\implies \quad \sf x=\dfrac{\cancel{2}(1\pm \sqrt{26})}{\cancel{2}\times 5}}[/tex]

[tex]{:\implies \quad \bf \therefore \quad \underline{\underline{x=\dfrac{1\pm \sqrt{26}}{5}}}}[/tex]

For any quadratic equation of the form ax² + bx + c , the Discriminant (D) is given by D = b² - 4ac , and the root [tex]\bf x[/tex] of the quadratic equation is given by the quadratic formula as

Answer:

63.7°

Step-by-step explanation:

supplementary_interier angle 180_116.3=63.7

Answer:

The number of students that prefer to do homework from the group of all students

Step-by-step explanation:

The question says that the ratio between the student who prefer doing homework before school and the students who prefer doing homework after school is 7:15.

That means 7 students prefer doing homework before school and 15 students prefer doing after school.

In this scenario, the total number of students is 7 + 15 i.e. 22

So the percentage 7/22 is the number of students that prefer to do homework before school from the group of all students

Answer:

D : -14

Step-by-step explanation:

(5+4-2)(-2) = x

7(-2) = x

-14 = x

x = -14

Answer:

4x+13

Step-by-step explanation:

Answer:

7x+15

Step-by-step explanation:

Answer:

44.58

Step-by-step explanation:

[tex]v=\frac{4}{3}\pi r^{3}\\ given r= 2.2\\\pi =3.14\\hence:v=\frac{4}{3} (3.14)(2.2)^3=44.58[/tex]

Answer:

Line D

Step-by-step explanation:

Two points that passes through line D :  (0,-2) & ( -4 , 0)

[tex]Slope =\dfrac{y_{2}-y_{1}}{x_{2}-x_{1}}\\\\\\=\dfrac{0-[-2]}{-4-0}\\\\\\=\dfrac{0+2}{-4}\\\\\\=\dfrac{2}{-4}\\\\\\=\dfrac{-1}{2}[/tex]

Answer:

BFG

Step-by-step explanation:

The segment BF is the diagonal of the top face of the cube (GBCF)

Therefore, it is the hypotenuse of ΔBFG and ΔBFC

See attached diagram for visual of the cube.

Answer:

4

Step-by-step explanation:

[tex] ln(x) = ln(16) + ln(4) [/tex]

Use the Produxt Rule

[tex] ln(a) + ln(b) = ln(a + b) [/tex]

Remeber that Ln is a log function with base e,

so know we have

[tex]3 ln(x) = ln(64) [/tex]

[tex] ln(a) = ln(b) [/tex]

Only if a=b So we have

x^3=64

x=4

[tex]x = 64[/tex]

Step-by-step explanation:

See the picture for steps

Answer:

The rule says that to find the number of years required to double your money at a given interest rate, you just divide the interest rate into 72. For example, if you want to know how long it will take to double your money at eight percent interest, divide 8 into 72 and get 9 years

Answer: 25.5 feet

Step-by-step explanation:

if each hat requires 30 inches of material, then 3 hats will require 3(30) = 90 inches.

if each scarf requires 2 yds of material, then 3 scarfs will need 3(2) = 6 yds.

The question wants us to give our answer in feet, so we will be converting:

Using 12in = 1ft:

90 in = 90/12 feet = 7.5 feet

Using 1 yd = 3 ft:

6 yds = 6(3) = 18 feet.

Now that the units are the same, we can add them up to get our answer:

7.5 + 18 = 25.5 feet

So Terry will need 25.5 feet of material to make 3 sets of hat and scarves.

[tex]\fbox{Answer ~}[/tex]

Here ,

[tex]\bold\purple{3x + 12 + 7 = - 5x - 5} \\\\\bold{3x + 19 = - 5x - 5}[/tex]

gather and solve the like terms together ,

[tex]\bold{3x + 5x = - 5 - 19} \\\\ \bold{8x = - 24} \\\\\bold{ x = \cancel{ \frac{ - 24}{8} }} \\ \\\bold\red{ x = - 3}[/tex]

hope helpful~