Question

七年级因式分解 (X+Y)平方-9Y的平方 （X+Y)平方-（X-Y）平方 25（a+B)平方-4（2A-B) X平方Y

Answer 1

解答;

(X+Y)^2-9Y^2=(x+y+3y)(x+y-3y)

=(x+4y)(x-2y)

（X+Y)^2-（X-Y）^2

=x^2+2xy+y^2-x^2+2xy-y^2=4xy

（X-Y)^2-81X^2Y^2=(x-y+9xy)(x-y-9xy)

n^3（M-2)-N(M-2)

=n(m-2)(n^2-1)=n(m-2)(n+1)(n-1)

4(a-B）^2-9（a+b）^2

=(2a-2b+3a+3b)(2a-2b-3a-3b)

=-(5a+b)(a+5b)