0=7x2+15x+6

Solution for 0=7x2+15x+6 equation:

0=7x^2+15x+6

We move all terms to the left:

0-(7x^2+15x+6)=0

We add all the numbers together, and all the variables

-(7x^2+15x+6)=0

We get rid of parentheses

-7x^2-15x-6=0

a = -7; b = -15; c = -6;
Δ = b2-4ac
Δ = -152-4·(-7)·(-6)
Δ = 57
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-15)-\sqrt{57}}{2*-7}=\frac{15-\sqrt{57}}{-14}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-15)+\sqrt{57}}{2*-7}=\frac{15+\sqrt{57}}{-14}
$