Jacob earned $80 babysitting and deposited the money into the his savings account. The next week he spent $85 on video games. Use integers to describe the weekly changes in Jacob's savings account balance.
Assume that the original amount in the account is x.
We will use: + to indicate addition of amount (increase in the amount of money) - to indicate subtraction of amount (decrease in the amount of money)
We have two changes: 1- The first week, he earned $80 and deposited them into the account. This means that he added $80 to the already existing amount. Therefore: amount in account = x + $80 The integer representing this increase would be +80
2- The second week, he withdrew $85 from the account. This means that he removed $85 from the already existing amount Therefore: amount in account = (x+$80) - $85 The integer representing the decrease would be -85
3- getting the change that occurred: change in account = x + 80 - 85 = x - $5 This means that for the two weeks together, the amount of money in the account decreased by $5
