Find the x intercepts if the equation is 8x=-x^2+20

Times both sides by -1
-8x=x²-20
add 8x both sides
0=x²+8x-20
factor
what 2 numbers multiply to get -20 and add to get 8
-2 and 10
0=(x-2)(x+10)
set to zero

x-2=0
x=2

x+10=0
x=-10

x intercepts at x=-10 and 2 or at the points
(-10,0) and (2,0)