9x 4 −6x 2 y 4 +y 8 9, x, start superscript, 4, end superscript, minus, 6, x, squared, y, start superscript, 4, end superscript, plus, y, start superscript, 8, end superscript we can factor the expression as ( u − v ) 2 (u−v) 2 left parenthesis, u, minus, v, right parenthesis, squared where u uu and v vv are either constant integers or single-variable expressions