Over the last three evenings, Diane received a total of 105 phone calls at the call center. The third evening, she received 4 times as many calls as the second evening. The first evening, she received 9 fewer calls than the second evening. How many phone calls did she receive each evening?'

Make an eqaution from here.
Let’s make evening 2 “x”

So the first evening has 9 less then the secon evening so…
x-9
Of course theres the second evening (x).

X-9+x
Then the third evening has 4 times as much as the second meeting so…
x-9+x+4x

And when solved, it has to equal 105.

So solve from here.
Combine like terms.

6x-9=105
Isolate

6x=114
x= 19

First evening is 9 less then 19, so 10.

The second evening was 19 calls.
The third evening was 4 times the second evening so, 19*4= 76

1st night = 10

2nd night= 19 calls
Thrid night= 76 calls