3d(-2d+5)=-6d+5

Solution for 3d(-2d+5)=-6d+5 equation:

3d(-2d+5)=-6d+5

We move all terms to the left:

3d(-2d+5)-(-6d+5)=0

We multiply parentheses

-6d^2+15d-(-6d+5)=0

We get rid of parentheses

-6d^2+15d+6d-5=0

We add all the numbers together, and all the variables

-6d^2+21d-5=0

a = -6; b = 21; c = -5;
Δ = b2-4ac
Δ = 212-4·(-6)·(-5)
Δ = 321
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$d_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$d_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$d_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(21)-\sqrt{321}}{2*-6}=\frac{-21-\sqrt{321}}{-12}
$
$d_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(21)+\sqrt{321}}{2*-6}=\frac{-21+\sqrt{321}}{-12}
$