3.) what are the solutions to x^2 + 8x + 7 = 0?
x = –8 and x = –7
x = –7 and x = –1
x = 1 and x = 7
x = 7 and x = 8

Check if x = -8 is the solution
1. substitute number -8 for x in the equation
(-8)^2 + 8*(-8) + 7 = 0
2. do calculations on the left size
64 -64 + 7 = 0
7 = 0
3. equality means x is the solution, inequality means it is not
-8 is not the solution to x^2 + 8x + 7 = 0

check other given numbers the same way
x=-7
(-7)^2 + 8*(-7) + 7 = 0
0=0
-7 is the solution

x=-1
(-1)^2 + 8*(-1) + 7 = 0
0=0
-1 is the solution

x=1
(1)^2 + 8*(1) + 7 = 0
16=0
1 is not the solution

x=7
(7)^2 + 8*(7) + 7 = 0
113=0
7 is not the solution

x=8
(8)^2 + 8*(8) + 7 = 0
135=0
8 is not the solution

The solutions to given equation are -7 and -1.