Question

(x+4)(2x-1)=x(3x+1)

Answer 1

(x+4)(2x-1)=x(3x+1)

2x²+7x-4 = 3x²+x

2x²+7x-4-3x²-x=0

-x²+6x-4=0

x²-6x+4=0

D=√36-16 = √20

$x1=\frac{6-\sqrt{20}}{2} = 3-\sqrt{5}\\   x2=\frac{6+\sqrt{20}}{2} = 3+\sqrt{5}$