Question

2x × (3x+1)-18=x^2 - 7-2×(x + x^2)

Answer 1

2x·(3x+1) - 18=x²-7-2·(x+x²)
6x²+2x-18=x²-7-2x-2x²
6x²-x²+4x+2x²+7-18=0
7x²+4x-11=0
D=16+4·7·11=324
x1=(-4+18):14=1
х2=(-4-18):14=-22/14=- 11/7=-1 4/7