3.
a)=-7a-4a-3b+20b=-11a+17b
b)=18a-3a+7b-4a+2b=11a+9b
4.
=2x-10-21-7x+5=-5x-26
5.
=-18+9b+8-14b+5b=-10
6.
=6a-3b-5a-15b=a-18b
Ответ:
.................................
А - 4
Б - 1
В - 2
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(5х-2)(х+1)-(5-2х)²=5х²+5х-2х-2-(25-20х+4х²)=5х²+5х-2х-2-25+20х-4х²=х²+23х-27.
Ответ: 1) х²+23х-27.
X^2 + (25x^2 - 30x + 9) = 26x^2 - 30x + 9