Объяснение:
1) x(a+b)-a-b=x(a+b)-(a+b)=(x-1)(a+b)
2) x(m+n)-7m-7n=x(m+n)-7(m+n)=(x-7)(m+n)
3) ax-2a+3x-6=a(x-2)+3(x-2)=(a+3)(x-2)
4) 2mx-3m-4x+6=m(2x-3)-2(2x-3)=(m-2)(2x-3)
5) 12a2b2-6abc+3ac2-6a2bc-c+2ab= 6ab(2ab-c)-3ac(2ab-c)+(2ab-c)=(6ab-3ac+1)(2ab-c)
6) xyz+x2y2+3x4y5+3x3y4z-xy-z=xy(z+xy)+3x3y4(xy+z)-(xy+z)=(xy+3x3y4-1)(xy+z)
1) 12*2-6x=0
24-6x=o
-6x=-24
x=4
2) 10*2+x=0
20+x=0
x=-20
3) y(5-y)=0
y=0 або 5-y=0
y=5