15m=3m(m-8)

Solution for 15m=3m(m-8) equation:

15m=3m(m-8)

We move all terms to the left:

15m-(3m(m-8))=0


We calculate terms in parentheses: -(3m(m-8)), so:

3m(m-8)

We multiply parentheses

3m^2-24m

Back to the equation:

-(3m^2-24m)


We get rid of parentheses

-3m^2+15m+24m=0

We add all the numbers together, and all the variables

-3m^2+39m=0

a = -3; b = 39; c = 0;
Δ = b2-4ac
Δ = 392-4·(-3)·0
Δ = 1521
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$m_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$m_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1521}=39$
$m_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(39)-39}{2*-3}=\frac{-78}{-6}
=+13
$
$m_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(39)+39}{2*-3}=\frac{0}{-6}
=0
$