x^2-30=7x
we will try to get it eqpal to zero
subtract 7x form both sdies
x^2-7x-30=0
factor because is xy=0 then x and/or y=0
so
find what 2 numbers add to -7 and multiply to -30
the numbers are -10 and 3
(x-10)(x+3)=0
so set them to zero
x-10=0
add 10
x=10
x+3=0
sbtract 3
x=-3
x=10 or -3