x^2+16=15x

Solution for x^2+16=15x equation:

x^2+16=15x

We move all terms to the left:

x^2+16-(15x)=0

a = 1; b = -15; c = +16;
Δ = b2-4ac
Δ = -152-4·1·16
Δ = 161
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{161}}{2*1}=\frac{15-\sqrt{161}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-15)+\sqrt{161}}{2*1}=\frac{15+\sqrt{161}}{2}
$