M=5i-4j
m=(5;-4)
................
1. (7а+7х)\(5а+5х)=7(a+x)/5(a+x)=1,4
2. (3а-6b)\(8b-4a)=3(a-2b)/4(2b-a)=-3/4
3.( 8x^2-4xy)\12x^3=4x(2x-y)/12x³=(2x-y)/3x²
4. (a^2+2a+1)\(a^2-1)=(a+1)²/(a+1)(a-1)=(a+1)/(a-1)
5.( x^2-4)\(4-2x)=(x-2)(x+2)/2(2-x)=-(x+2)/2
6. (3+3n+3n^2)\(n^3+1)=3(1+n+n²)/(n+1)(n²-n+1)
Если n³-1,то ответ 3/(n-1)
15m²n-5mn=5mn(3m-1)
(3.5.m.m.n-5.m.n.1=5.m.n(3m-1)=5mn(3m-1)
2x(x^2-3)-x(1-x)=2(x^2-3)
2x^3-6x-x+x^2=2x^2-6
2x^3-x^2-7x+6=0
2(x^2+х-3)(х-1)=0
или
2x(x^2-3)-x(1-x)=2(x^2-3)
2x(x^2-3)-x(1-x)-2(x^2-3) =0
(x^2-3)(2х-2)-x(1-x)=0
(x^2-3)2(х-1)+x(х-1)=0
2(x^2-3+х)(х-1)=0
х=1