分解因式①25x²-y²;②(a-b)(x-y)+(a-b)(x+y);③(x+2y)²-8xy
问题描述:
分解因式①25x²-y²;②(a-b)(x-y)+(a-b)(x+y);③(x+2y)²-8xy
答
①平方差 (5x+y)(5x-y)
②提公因式(a-b)2x
③开括号再整理x^2+4xy+4y^2-8xy=x^2-4xy+4y^2=(x-2y)^2
可追问 望采纳
答
①25x²-y²=(5x+y)(5x-y)②(a-b)(x-y)+(a-b)(x+y)=(a-b)[(x-y)+(x+y)]=2x(a-b)③(x+2y)²-8xy=x²+4xy+4y²-8xy=x²-4xy+4y²=(x-2y)²