4a^2=( )^2 16/25X^4Y^2=( )^2 36(X+2Y)^2=[ ]^2 49(X-3Y)^2=[ ]^2 因式分解,

问题描述:

4a^2=( )^2 16/25X^4Y^2=( )^2 36(X+2Y)^2=[ ]^2 49(X-3Y)^2=[ ]^2 因式分解,

4a^2=( 2a)^2
16/25X^4Y^2=(4/5x^2y )^2
36(X+2Y)^2=[6x+12y ]^2
49(X-3Y)^2=[7x=21y ]^2请问-m^2-n^2分解因式之后是-(m+n)(m-n)吗?THANK YOU`是 完全正确