The answer to number 23 is D, 49.
Y=-3x-2
subsitute -3x-2 for y
-7x+3(-3x-2)=10
distribute
a(b+c)=ab+ac
3(-3x-2)=-9x-6
-7x-9x-6=10
add like terms
-16x-6=10
add 6
-16x=16
multiply -1
16x=-16
divide 16
x=-1
subsitute
y=-3x-2
y=-3(-1)-2
y=3-2
y=1
x=-1
y=1
(x,y)
(-1,1)
Find percent -> 2nd month.
4264*.25==1066 phone calls+=4264
==5330 for 2nd month.
for 2nd -> 3rd
6396==5330*x, solve algebraically to get .20 == 20% increase from 2nd month to 3rd month.