40 ! jason bought a 7 new baseball cards to add to his collection. the next day, his sweet dog ate ½ of his collection. there are now only 25 cards left. how many cards did jason start with?

define your variable, write an equation and solve for you unknown. write your answer in a complete sentence.

Let b = the number of baseball cards he started with

1/2 (b+7) =25

Jason started with 43 baseball cards.

Step-by-step explanation:

Let b = the number of baseball cards to start with

He bought 7 new cards

b+7

Now the dog at 1/2

1/2(b+7)

There are 25 cards left

1/2 (b+7) =25    This is our equation

Multiply each side by 2

2*1/2 (b+7) =25*2

b+7 = 50

Subtract 7 from each side

b+7-7 = 50-7

b = 43

Jason started with 43 baseball cards.