1/8-а⁶=(1/2-а²)(1/4+а²/2+а⁴) формула разности кубов
*2 -квадрат будет
3)5x*2+5xy*2-25x
5)-3xy*3-2x*2y
7)16x*2y-12xy*2+20x*2y*2
13.2
1) x*2-xy-ax-ay
3)bt+tr+sb+sr
5)ab-3a+2b-
7)dt+5d-4t+20
13.3
1)x*2+8x-7x-56
3)4a-a*2+24-6a
5)90-10c-9c+c*2
13.4
b*3-b*2-7b+3b*2-3b-21.
1.405
2.60,39
3.2,2
4.27,366
5.5,548
6.33210+7290=40500
7.29/126*21/29=1/6
8.-18,9
9.-4,5
2. (4+2m)+(2n+mn) = 2(2+m)+n(2+m) = (2+n)(2+m)
4. (ab+ac)+(7b+7c)=a(b+c) + 7(b+c) = (a+7)(b+c)
6. (xz+yz)-(3x+3y) = z(x+y)-3(x+y) = (z-3)(x+y)