2x2+7=15x

Solution for 2x2+7=15x equation:

2x^2+7=15x

We move all terms to the left:

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

a = 2; b = -15; c = +7;
Δ = b2-4ac
Δ = -152-4·2·7
Δ = 169
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{169}=13$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-15)-13}{2*2}=\frac{2}{4}
=1/2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-15)+13}{2*2}=\frac{28}{4}
=7
$