1)(a-2)²=a²-4a+4
2)(a-3)(a+3)=a²-9
3)(x-1)(x²+x+1)=x³-1
4)2.(c-2)(2+c)=2.(c²-4)=2c²-8
5)(x²+3)²=xˇ4 + 6x²+9
6)(a-3)(a+6)=a²+3a-18
A²-ab-ab+b²=a²-2ab+b²
Ответ:а²-2аb+b²
b²+b²=2b²
1) 7(x + 1) - 2(x - 4) = x - 9
7x + 7 - 2x + 8 = x - 9
5x - x = - 9 - 15
4x = - 24
x = - 6
2) 3(x - 1) - 2(x - 5) = 5x + 13
3x - 3 - 2x + 10 = 5x + 13
x - 5x = 13 - 7
- 4x = 6
x = - 1,5
3) 2 = (3x - 5) - (7 - 4x)
2 = 3x - 5 - 7 + 4x
2 = 7x - 12
7x = 2 + 12
7x = 14
x = 2
x^4-y^4=(x^2-y^2)(y^2+y^2)=2*(x^2+y^2)