Question

因式分解~~

1.（p-4)（p+1）+3p
2.(2a-b)平方+8ab
3.4xy平方-4x平方y-y三次方

Answer 1

1.原式=p^2-4
=(p+2)(p-2)
2.原式=(2a-b)^2+8ab
=4a^2-4ab+b^2+8ab
=4a^2+4ab+b^2
=(2a+b)^2
3.原式=4xy^2-4x^2y-y^3
=y(4xy-4x^2-y^2)
=-y(y^2-4xy+4x^2)
=-y(y-2x)^2

Answer 2

1.(p-4)(p+1)+3p=p^2-3p-4+3p=p^2-4
=(p+2)(p-2)
2.(2a-b)^2+8ab=4a^2-4ab+b^2+8ab
=4a^2+4ab+b^2=(2a+b)^2
3.4xy^2-4x^2y-y^3=-y(-4xy+4x^2+y^2)
=-y(2x-y)^2