8r2+15=29r

Solution for 8r2+15=29r equation:

8r^2+15=29r

We move all terms to the left:

8r^2+15-(29r)=0

a = 8; b = -29; c = +15;
Δ = b2-4ac
Δ = -292-4·8·15
Δ = 361
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{361}=19$
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-29)-19}{2*8}=\frac{10}{16}
=5/8
$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-29)+19}{2*8}=\frac{48}{16}
=3
$