Question

Даю 60балов!!!!!!!!!​

Answer 1

$\displaystyle\bf\\5a^{2} -5b^{2} -15a^{3} b+15ab^{3} =5\cdot\Big[(a^{2} -b^{2} )-(3a^{3} b-3ab^{3})\Big] =\\\\\\5\cdot\Big[(a^{2} -b^{2} )-3ab\cdot(a^{2} -b^{2} )\Big]=5\cdot(a^{2} -b^{2} )(1-3ab)=\\\\=5(1-3ab)(a-b)(a+b)$