This student incorrectly simplified this expression.


−12m+3+5m
Step 1: −7m + 3
Step 2: −4m
Identify the student's error.
Explain what they did wrong.

Answer:

B) a + 2(a - 3) = 15

Step-by-step explanation:

To see which equation has a = 7, we have to plug 7 into a each time until we find a satisfied equation.

A:

B:

Therefore, B is the correct answer.

Answer:

58º

Step-by-step explanation:

angles on a straight line = 180º

90 + 32 = 122

180 - 122 = 58

Answer:

F has the smalled minimum value

Step-by-step explanation:

Answer:

No

Step-by-step explanation:

No, because the rates are not the same for X and Y

Answer: Melissa's walking speed is 2mph. Her biking speed is 6mph

Step-by-step explanation:

Her total distance is 6 miles, because she walks 3 miles, and so the returning distance must also be 3.

Let her cycling speed (in mph) be x

Let her walking speed (in mph) be y

We know that x = y + 4

Since we know that S = D/T:

T = D/S

So her cycling time must be: T = 3/x

and her walking time must be: T = 3/y

since we know that x = y + 4, we can substitute this into her cycling time, and rewrite it as T = 3/y+4

we also know that 3/y+4 + 3/y = 2, because the problem says that the total time taken was 2 hours.

We simply need to solve this equation now:

3/y+4 + 3/y = 2

The LCD for y+4 and y is y² + 4y

so now we have:

(3y/y² + 4y) + (3y+12/y² + 4y) = 2

(6y + 12)/y² + 4y = 2

6y + 12 = 2y² + 8y

2y² + 2y - 12 = 0

Solve this using factoring:

2y² + 2y - 12 = 0

2(y² + y - 6) = 0

(y+3)(y-2) = 0

using ab = 0, then a or b =0:

y = -3, or y = 2

Since speed cannot be negative, our answer is 2 for y. So y, or the walking speed is 2mph. Since x = y + 4, we know that x = 6 mph

Melissa's walking speed is 2mph. Her biking speed is 6mph

Answer:

Step-by-step explanation:

I don't know if this is what your looking for but the 38 cars that are 10 years old are 45.78 in percentage and the 5 cars that are more than 20 years are 6.02 in percentage.

(if you are asking how much more percentage to get from 6.02 to 45.78 its 39.76)

I really did not get the question but hope it help a bit.

Answer:

(A) 46% (B) 13%

Step-by-step explanation:

First we can find the percentage of cars that are at least 10 years old by dividing the amount that are 10+ years old by the total amount of cars

[tex]38/83= 0.45783[/tex]

when made into a percentage that is 46%

Now we can find the percentage of those cars that are 20+ years old by dividing the number of 20+ year old cars by our percentage

[tex]5/38=0.13157[/tex]

When made into a percentage That is 13%

Hope this helps! :)

Answer:

1/4 chance for Ephraim and 1/2 chance for Keiko

8

Step-by-step explanation:

you would do 10 divide by 2.25 and that's 4.4 but you can't by half a hamburger so you round down to 4 and then you times 4x2 because it's 2.25 for two hamburgers so your answer is 8.

Answer:

Yamateh kudasai

Step-by-step explanation:

hope it helps

Answer:

-5/2,-1/4

Step-by-step explanation:

The average rate of change is the slope.

The slope is equal [tex]\frac{y2-y1}{x2-x1}[/tex], if we were to do that for each set of points, we get the slope is always 8.

Thus the average rate of change is 8.

[tex] \rm \color{lime}(2,10)[/tex]

step-by-step explanation:

[tex]\rm \color{lime}y = - {x}^{2} + 4x + 6[/tex]

[tex]\rm \color{lime}x = - \frac{4}{2x( - 1)} [/tex]

[tex]\rm \color{lime}y = - {x}^{2} + 4x + 6,x = 2[/tex]

[tex]\rm \color{lime}y = 10[/tex]

[tex] = \rm \color{hotpink} (2,10)[/tex]

hope it helps

Answer:

y = - (x - 2)² + 10

Step-by-step explanation:

the equation of a parabola in vertex form is

y = a(x - h)² + k

where (h, k ) are the coordinates of the vertex and a is a multiplier

To obtain this form use the method of completing the square

y = - x² + 4x + 6 ( factor out - 1 from the first 2 terms )

y = - (x² - 4x) + 6

To complete the square

add/subtract ( half the coefficient of the x- term )² to x² - 4x

y = - (x² + 2(- 2) + 4 - 4) + 6

y = - (x - 2)² + 4 + 6

y = - (x - 2)² + 10 ← in vertex form

Answer:

52

Step-by-step explanation:

Answer:

225

Step-by-step explanation:

A = 5. 3A = 3(5) cubed. So 3 times 5 is 15. 15 cubed is 225.

Answer:

the slope is m= 2/3

if you need it for y is y=2/3x-20/3

Step-by-step explanation:

both of a and b are correct but I don't know how...

Answer:

hello

Step-by-step explanation:

I'd put chemical or physical process in which rocks are worn down by in erosion and carrying away of soil rock and other materials in weathering.

Hope this helps

Resolviendo una ecuación cuadratica, veremos que el número puede ser -2 o 1/8.

Partimos de la oración matematica:

"Ocho veces un número es restado de dos veces su recíproco. El resultado es 15. Halla el número."

Primero vamos a definir al número como x.

El reciproco de x es la inversa, es decir, 1/x.

Entonces, a 2 veces ek reciproco de x, le restamos 8 veces x, y eso va a ser igual que 15.

2/x - 8*x = 15

Ahora podemos resolver esto para x, primero multiplicamos a ambos lados por x:

2 - 8x^2 = 15x

-8x^2 - 15x + 2 = 0

Esto es una ecuación cuadratica, las soluciones van a ser:

[tex]x = \frac{-(-15)\pm \sqrt{(-15)^2 - 4*(-8)*2} }{2*(-8)} \\\\x = \frac{15\pm 17}{-16}[/tex]

Entonces tenemos dos soluciones:

x = (15 + 17)/-16 = -2

x = (15 - 17)/(-16) = 1/8

El número puede ser -2 o 1/8.

Sí quieres aprender más sobre ecuaciones cuadraticas, puedes leer:

https://brainly.com/question/14013122

Answer:

Distance between parallel chords is 14 cm or 2 cm. Hope this helps

Step-by-step explanation:

Answer:

n+(n-5)

=2n-5

n years Mary's age

n-5 years younger sisters age

Thanks!

Answer/Step-by-step explanation:

Given:

Maria is 5 years older than her younger sister.

If Maria will be n years after 7 years,

To Find:

Find their total age in terms of n.​

Solve:

n+(n-5)

n + n = 2n

2n -5

n -  years Mary's age

Therefore,  n-5 years younger sisters age

[RevyBreeze]

Answer:

Step-by-step explanation:

Answer:

2. 131

3. 8

4. 69

Step-by-step explanation:

2.

√5607

=131

3.

10cm, √9cm, 8cm

4.

372−1300

=1369−1300

=69

Answer:

can you show a picture

Step-by-step explanation:

it depends on the situation and the problem but normally you would use the other numbers to figure out what number goes in "x"

Need more information to solve for x.

Shelly would need 5 pounds of grass seed to plant in her backyard.

Area is the amount of space occupied by a two dimensional shape or figure.

From the image:

Area of the backyard = (10 + 15) * (10 + 20) = 750 ft²

Area of triangle = (1/2) * 10 * 10 = 50 ft²

Area of small rectangle = (25 - 20) * (30 - 15) = 75 ft²

Area of shaded part = 750 - 50 - 75 = 625 ft²

1 pound of grass seed covers 125 ft², for 625 ft²:

Amount of seed = 625 ft² * 1 pound per 125 ft²  = 5 pound

Shelly would need 5 pounds of grass seed to plant in her backyard.

Find out more on area at: https://brainly.com/question/25292087

Answer:

To solve your inequality using the Inequality Calculator, type in your inequality like x+7>9. The inequality solver will then show you the steps to help you learn how to solve it on your own.

Step-by-step explanation:

Answer: See below

Step-by-step explanation:

The usage of passive income instead of collecting and saving your money without risking a loss through investments:

Passive income is money that you make without having to perform a lot of "active" work to keep it. In essence, you may complete the most of the work upfront and put in some extra effort along the secondary source of income.