The answer is 20 because if there is four options that you can spin on and he has spinned 80 times 8÷4 is 20
Difference of 2 perfect squres
if yo have
a^2-b^2 that equals (a-b)(a+b)
x^2-1^2=(x-1)(x+1)
tada
f(x)=(x+4) ^2 −25
to solve set equal to zero
0 =(x+4) ^2 −25
add 25 to each side
25 = (x+4) ^2
take the square root of each side
square root (25) =(x+4)
+- 5 = (x+4)
5 = x+4 -5 = x+4
subtract 4 from each side
1 =x -9 =x
