Expressions and Equations Test Review

Expressions and Equations Test Review

by James Wallace

​Solve.

​100 = -2.5x

​

​What is the first thing I do?

Multiple Choice

100 = -2.5x

​

​What is the first thing I do?

• Divide by 2.5

  on both sides

• Divide by -2.5

  on both sides

​Answer.

​Be sure to cross out the -2.5's on the variable's side

​Simplify.

​18m - 9v + 6v -12m

​

​What's the first thing I do?

Multiple Choice

​18m - 9v + 6v -12m

​

​What's the first thing I do?

• Match the LIKE terms INCLUDE the sign!

  (ex: put the same shape around like terms)

• Match the LIKE terms FORGET the sign!

  (ex: put the same shape around like terms)

Answer:

Match the LIKE terms INCLUDE the sign!

(ex: put the same shape around like terms, I used the same color for mine)

​

​

​18m - 9v + 6v -12m

​Next, what do I do?

​18m - 9v + 6v -12m

Multiple Choice

​Next, what do I do?​

18m - 9v + 6v -12m

• Combine the like terms

• I'm finished

​Combine like terms!

​​18m - 9v + 6v -12m

​

​ 18m -9v

​-12m +6v

​=6m =-3v

​So the answer is: 6m - 3m

​Solve.

​Mark's brother is seven years older than Mark. Their combined ages add up to 28. How old is Mark?

Multiple Choice

​Mark's brother is seven years older than Mark. Their combined ages add up to 21. How old is Mark?

What is a good way to write this?

• Mark's age

  +

  Mark's brother's

  age

  = 21

• Mark's Brother + 7 = 21

​Answer.

​

Mark's age

+

Mark's brother's

age

​

= 21

​How do we solve?

​Well, if Mark is m years old,

then Mark's Brother is m + 7 years old.

​

​Now we combine them!

Oh, we have like terms. So combine like terms like before.

​m + m + 7 = 21

​2m + 7 = 21

Multiple Choice

Well, if Mark is m years old, then Mark's Brother is m + 7 years old.

​

​Now we combine them.....Like this!

• m + 7 = 21

• m + m + 7 = 21