В) x^2+2x+x+2=2x^2-4x-x+2
-x^2+8x=0
x(-x+8)=0
x1=0 x2=8
<span>8x=6+2(4x-3)
8x=6+8x-6
0=0
x</span>∈R
1) a³+8b³=(a+2b)(a²-2ab+4b²)
2) x²y-36y³=y(x²-36y²)=y(x-6y)(x+6y)
3)-5m²+10mn-5n² /÷(-5)
-5m²+10mn-5n²=m²-2mn+n²=(m-n)²
4) 4ab-28b+8a-56 /÷4
4ab-28b+8a-56=(ab-7b)+(2a-14)=b(a-7)+2(a-7)=(a-7)(b+2)
5)a⁴-81=(a²)²-(3²)²=(a²-3²)(a²+3²)=(a²-9)(a²+9)=(a-3)(a+3)(a²+9)