Question

Over the last 3  evenings, Keisha received a total of 81  phone calls at the call center. The first evening, she received 6  fewer calls than the second evening. The third evening, she received 3  times as many calls as the first evening. How many phone calls did she receive each evening

Answer 1

First: 15

Second: 21

Third: 45

Explanation:

In order to create the equation we need to represent the evenings with an alebraic term, in thsi case we are going to represent the second evening with an X

Second evening:x

The first night she got 6 fewer calls than the second: Second-6=x-6

The third night she received 3 times the first: 3(first night)=3(x-6)

The equation is First Night plus second night plus third night equals 81.

`First+second+third=81\\x+(x-7)+3(x-6)=81\\x+x-7+3x-18=81\\5x=81+21+6\\5x=105\\x=(105)/(5) \\x=21`

So the first evening he received 15 calls, the second he received 21 and the third one he received 45.