福冈大丸百货:初一数学题

来源:百度文库 编辑:杭州交通信息网 时间:2024/05/06 01:38:50
因式分解:
(1)4(x-y)^2-9(x+y)^2
(2)16(x-y)^2-25(x+y)^2

1,原式=[2(X-Y)+3(X+Y)][2(X-Y)-3(X+Y)]=-(5X+Y)(X+5Y)
2 ,原式=[4(X-Y)+5(X+Y)][4(X-Y)-5(X+Y)]=-(9X+Y)(X+9y)

1 (2(X-Y)+3(X+Y))(2(X-Y)-3(X+Y))=(5X+Y)(-X-5Y)
2 (4(X-Y)+5(X+Y))(4(X-Y)-5(X+Y))=(9X+Y)(-X-9Y)