Question

Помогите пожалуйста! 25 БАЛЛОВ!

Answer 1

1.
$(3a + b)(2a - 5b) - 6(a - b) {}^{2} \\ 6a {}^{2} - 15ab + 2ab - 5 {b}^{2} - 6( {a}^{2} - 2ab + {b}^{2} ) \\ 6 {a}^{2} - 15ab + 2ab - 5 {b}^{2} - 6 {a}^{2} + 12ab - 6 {b}^{2} \\ - ab - 11 {b}^{2}$
2.
$( - 2 {a}^{3}b ) {}^{3} \times ( - 5 {a}^{2} b) {}^{2} \\ - (2a {}^{3} b) {}^{3} \times (5 {a}^{2} b) {}^{2} \\ - 8a {}^{9} b {}^{3} \times 25 {a}^{4} {b}^{2} \\ - 200a {}^{13} b {}^{5}$
3.
$ab + ac - a \\ a(b + c - 1)$
4.
$4 {a}^{2} - {b}^{2} + 2a - b \\ (2a - b)(2a + b) + 2a - b \\ (2a - b)(2a + b + 1)$