Question

дуже потрібна допомога допоможіть​

Answer 1

Ответ:

1) 58a²

2) 25a–8

Объяснение:

1) (–2b+7a)²–(–3a+2b)(2b+3a)+28ab=

(7a–2b)²–(2b–3a)(2b+3a)+28ab=

=49a²–28ab+4b²–(4b²–9a²)+28ab=

=49a²+4b²–4b²+9a²=49a²+9a²+4b²–4b²=

=49a²+9a²=58a²

2) (a–2)(a²+2a+4)–a(a–5)(a+5)=

=a³–2³–a(a²–25)=a³–8–a³+25a=

=a³–a³+25a–8=25a–8

Answer 2

$1)( - 2b + 7a) {}^{2} - ( - 3a + 2b)(2b + 3a) + 28ab = (7a - 2b) {}^{2} - (2b - 3a) \times (2b + 3a) + 28ab = 49 a{}^{2} - 28ab + 4b {}^{2} - (4b {}^{2} - 9a {}^{2} ) + 28ab = 49a {}^{2} + 4b {}^{2} - 4b {}^{2} + 9a {}^{2} = 58a {}^{2}$