# Explaining Steps for Rewriting Equations

# Explaining Steps for Rewriting Equations

##### Problem 1

Match each equation with an equivalent equation. Some of the answer choices are not used. Write the letter of the equation in the answer box.

a) $9x = 4x + 7 \quad \quad$ b) $3x + 18 = 4x + 7 \quad \quad$ c) $3x = 4x + 7 \quad \quad$ d) $3x - 1 = 4x \quad \quad$ e) $7x = 1$

1) $3x + 6 = 4x + 7$

2) $3(x + 6) = 4x + 7$

3) $4x + 3x = 7 - 6$

##### Problem 2

4) Mai says that equations A and B have the same solution.

- Equation A: $-3(x + 7) = 24$
- Equation B: $x + 7 = -8$

Which statement explains why this is true?

##### Problem 3

5) Is $0$ a solution to $2x + 10 = 4x + 10$?

6) Explain or show your reasoning.

##### Problem 4

7) Kiran says that a solution to the equation $x + 4 = 20$ must also be a solution to the equation $5(x + 4) = 100$.

Write a convincing explanation as to why this is true.

##### Problem 5

8) The entrepreneurship club is ordering potted plants for all 36 of its sponsors. One store charges $8.50 for each plant plus a delivery fee of $20. The equation $320 = x + 7.50(36)$ represents the cost of ordering potted plants at a second store.

What does the $x$ represent in this situation?

##### Problem 6

9) Which equation is equivalent to the equation $5x + 30 = 45$?

##### Problem 7

10) The environmental science club is printing T-shirts for its 15 members. The printing company charges a certain amount for each shirt plus a setup fee of $20.

If the T-shirt order costs a total of $162.50, how much does the company charge for each shirt?

##### Problem 8

The graph shows the relationship between temperature in degrees Celsius and temperature in degrees Fahrenheit.

11) Mark the point on the graph that shows the temperature in Celsius when it is 60 degrees Fahrenheit.

12) Mark the point on the graph that shows the temperature in Fahrenheit when it is 60 degrees Celsius.

13) Water boils at 100 degrees Celsius. Use the graph to approximate the boiling temperature in Fahrenheit, or to confirm it, if you knew what it is.

14) The equation that converts Celsius to Fahrenheit is $C = \frac{5}{9}(F - 32)$. Use it to calculate the temperature in Celsius when it is 60 degrees Fahrenheit. (This answer will be more exact than the point you found in the first part.)

##### Problem 9

15) Select **all** the equations that have the same solution as $2x - 5 = 15$. Write each corresponding letter in the answer box and separate letters with commas.

a) $2x = 10$ b) $2x = 20$ c) $2(x - 5) = 15$ d) $2x - 20 = 0$ e) $4x - 10 = 30$

f) $15 = 5 - 2x$

##### Problem 10

16) Diego’s age $d$ is 5 more than 2 times his sister’s age $s$. This situation is represented by the equation $d = 2s + 5$. Which equation is equivalent to the equation $d = 2s + 5$?