1.1)x*x+x-3x-3
x2+x-3x-3
=x2-2x-3
2)ab+4a-3*4
=ab+4a-3b-12
3)x2+3x-7x-21
=x2-4x-21
4)2y*5y-2y*6+5y-6
10y2-12y+5y-6
=10y2-7y-6
5)6a2-21ab-2ab+7b2
=6a2-23ab+7b2
2.1)x2-3x+6x-18-(x2+9x+3x+27)=9
x2-3x+6x-18-x2-12x-27=9
-9x-45=9
-9₽=9+45
-9x=54
x=-6
1.1)x*x+x-3x-3
x2+x-3x-3
=x2-2x-3
2)ab+4a-3*4
=ab+4a-3b-12
3)x2+3x-7x-21
=x2-4x-21
4)2y*5y-2y*6+5y-6
10y2-12y+5y-6
=10y2-7y-6
5)6a2-21ab-2ab+7b2
=6a2-23ab+7b2
2.1)x2-3x+6x-18-(x2+9x+3x+27)=9
x2-3x+6x-18-x2-12x-27=9
-9x-45=9
-9₽=9+45
-9x=54
x=-6