Creating Equations with Variables

Mr. Anderson had 185 pieces of wood.  He sold 25 pieces of wood to his neighbor and stacked the rest of the wood into piles around his house.  Each pile of wood contained 40 pieces of wood.  Which equation can be used to find p, the number of piles of wood Mr. Anderson made?

• p = (185+25)+40 

• p = (185−25)−40 

• p=(185+25)×40 

• p=(185−25)÷40 

A waiter has 85 people in his section today for lunch. If 23 of them leave and the remaining tables each have six people at each table, which equation would best represent t, the number of tables he has left to serve?

• t= (85-23)-6

• t= (85-23) / 6

• t= 85- (23 / 6)

• t= 85 - (23 X 6)

a number is added to 22 is the same as the product of 6 and a number

• 22+u

• 22+k = 6x

• 22+u=6 + x

• u+22=6

A​ town's population is 47,500. About 75 people move out of the town each month. Each​ month, 125 people on average move into town. A nearby town has a population of 50,250. It has no one moving in and an average of 200 people moving away every month. In about how many months will the populations of the towns be​ equal? Write an equation to model the situation. Then solve the equation and answer the question.

• 125m-75m+50,250=47,500-200m

• 75m-125m+ 50,250 = 47,500-200m

• 75m-125m+47,500 = 50,250-200m

• 125m-75m+47,500 = 50,250-200m

Rayshawn and Robert are both saving money for their summer vacations. They began saving at the same time. Rayshawn started with $10.25 and adds $5.15 to his savings every month. Robert did not have a starting amount but adds $10.25 to his savings every month. Which equation could be used to determine how many months, m, it will take before Rayshawn and Robert both have saved the same amount of money?

• 5.15m + 10.25 = 10.25m

• 10.25m + 5.15 = 10.25m

• 10.25m + 10.25 = 5.15m

• 10.25m – 5.15 = 10.25m

The 30 members of a choir are trying to raise at least $1500 to cover travel costs to a signing camp. They have already raised $600. Which inequality would you solve to find the average amount each member can raise in order to meet the goal?

• 30x + 600  ≥ 1500

• 30x + 600  ≤ 1500

• 30x  - 600  ≤ 1500

• 30x = 1500

5p + 4h - 2
Which are the variables? 

• 5p, 4h, 2

• 2

• p, h

• 5, 4

What are the variables in the following expression?

• 3, 4, 1 and 7

• z, x and y

• + and -

• 15

In this expression what is the variable? 
5 + y 

• q

• 5

• y

• +

What is the variable in 3x - 5

• x

• 5

• 3