分解因式：（1）a^2-144b^2 (2)-x^4+X^2 y^2 (3)3(a+b)^2-27^2

(1）a^2-144b^2
=(a+12b)(a-12b)

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

(3)3(a+b)^2-27^2
=3[(a+b)^2-
最后一道是27^2吗
3(a+b)^2-27
=3[(a+b)+3][(a+b)-3]
=3(a+b+3)(a+b-3)

1.a^2-144b^2=(a+12b)(a-12b)

2.(xy+x^2)(xy-X^2)

（1）a²-144b²
=a²-(12b)²
=(a+12b)(a-12b)

(2)-x^4+X² y²
=-x²(x²-y²)
=-x²(x+y)(x-y)

(3)3(a+b)^2-27^2
=[√3(a+b)]²-27²
=[√3(a+b)+27][√3(a+b)-27]
=(√3a+√3b+27)(√3a+√b-27)