Question

因式分解：-14x^2y^2＋x^4＋y^4

Answer 1

-14x"y" + x^4 + y^4

= (x")" + 2(x")(y") + (y")" - 16(x")(y")

= ( x" + y" )" - ( 4xy )"

= ( x" - 4xy + y" )( x" + 4xy + y" )