3x(2x-1)-6x(7+x)=90;
6x^2-3x-42x-6x^2=90;
-45x=90;
x=-2
1,5x(3+2x)=3x(x+1)-30;
4.5x+3x^2=3x^2+3x-30;
1.5x=-30;
x=-20
5x(12x-7)-4x(15x-11)=30+29x;
60x^2-35x-60x^2+44x=30+29x;
-35x+44x=30+29x;
-20x=30
x=-1.5
24x-6x(13x-9)=-13-13x(6x-1)
24x-78x^2+54x=-13-78x^2+13x
24x+54x=-13+13x
65x=-13
x=-0.2
3x(2x-1)-6x(7+x)=90;
6x^2-3x-42x-6x^2=90;
-45x=90;
x=-2
1,5x(3+2x)=3x(x+1)-30;
4.5x+3x^2=3x^2+3x-30;
1.5x=-30;
x=-20
5x(12x-7)-4x(15x-11)=30+29x;
60x^2-35x-60x^2+44x=30+29x;
-35x+44x=30+29x;
-20x=30
x=-1.5
24x-6x(13x-9)=-13-13x(6x-1)
24x-78x^2+54x=-13-78x^2+13x
24x+54x=-13+13x
65x=-13
x=-0.2