Question

3x(3+x)-x(3+x)=2(x-4)-4

Answer 1

3x(3+x)-x(3+x)=2(x-4)-4
(3-1)x×(3+x)=2x-8-4
2x×(3+x)=2x-12
6x+2x²=2x-12
6x+2x²-2x+12=0
4x+2x²+12=0
2x²+4x+12=0
2(x²+2x+6)=0
x²+2x+6=0
D = b²-4ac
D = 2²-4×1×6 = 4-24 = -20
x ∉ R