Question

分解因式 1、16[（x+y）的平方]-25[（x-y）的平方] 2、[（5m方+3n方）的平方]-[（3m方+5n方）

Answer 1

16[(x+y)²]-25[(x-y)²]

=[4(x+y)+5(x-y)][4(x+y)-5(x-y)]

=(9x-y)(9y-x)

[(5m²+3n²)²]-[(3m²+5n²)²]

=[(5m²+3n²)+(3m²+5n²)][(5m²+3n²)-(3m²+5n²)]

=(8m²+8n²)(2m²-2n²)

=[8(m²+n²)][2(m²-n²)]

=16(m²+n²)(m+n)(m-n)