用平方差公式：
36（x+y）^2-49(x-y)^2
=[6(x+y)]^2-[7(x-y)]^2
=[6(x+y)+7(x-y)][6(x+y)-7(x-y)]
=(13x-y)(13y-x)
因式分解:36(x+y)²-49(x-y)²
用平方差公式：
36（x+y）^2-49(x-y)^2
=[6(x+y)]^2-[7(x-y)]^2
=[6(x+y)+7(x-y)][6(x+y)-7(x-y)]
=(13x-y)(13y-x)