1) -2x-5(x+2)-4=
= -2x-5x-10-4=
=-7x-14=
=-7(x+2).
2) 2(x-3)x(x+2) =
=(2x-6)(x la a doua+2x)
=2x la a doua +4x la a doua-6x-12x=
=6x(la2) -18x=
=6x(x-3) .
3. |x-2|=1
<=>-1>x-2>1
<=>-1+2>x>1+2
<=>1>x>3 => x=2
4) x+35=42
x=42-35
x= 7
5)x+2=1
x=1-2
x=-1
6) (x-2)x(x+2)=
=(x-2)(x+2)x=
= (x la a doua - 4) x =
= x la a treia -4x.