Question

-8 = x+66/
-9

Answer 1

is that \[\large -8=\frac{ x+66 }{ -9 }\]

?

Answer 2

Multiply the whole equation by (-9). Hence,
-8(-9) = x+66
72 = x + 66 (subtract the left and right side by 66)
72-66 = x+66-66
72-66 = x
x=?