330=2x(5x+8)

Solution for 330=2x(5x+8) equation:

330=2x(5x+8)

We move all terms to the left:

330-(2x(5x+8))=0


We calculate terms in parentheses: -(2x(5x+8)), so:

2x(5x+8)

We multiply parentheses

10x^2+16x

Back to the equation:

-(10x^2+16x)


We get rid of parentheses

-10x^2-16x+330=0

a = -10; b = -16; c = +330;
Δ = b2-4ac
Δ = -162-4·(-10)·330
Δ = 13456
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{13456}=116$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-16)-116}{2*-10}=\frac{-100}{-20}
=+5
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-16)+116}{2*-10}=\frac{132}{-20}
=-6+3/5
$