-10x(x+3)+28=-16-16

Solution for -10x(x+3)+28=-16-16 equation:

-10x(x+3)+28=-16-16

We move all terms to the left:

-10x(x+3)+28-(-16-16)=0

We add all the numbers together, and all the variables

-10x(x+3)+28-(-32)=0

We add all the numbers together, and all the variables

-10x(x+3)+60=0

We multiply parentheses

-10x^2-30x+60=0

a = -10; b = -30; c = +60;
Δ = b2-4ac
Δ = -302-4·(-10)·60
Δ = 3300
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{3300}=\sqrt{100*33}=\sqrt{100}*\sqrt{33}=10\sqrt{33}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-30)-10\sqrt{33}}{2*-10}=\frac{30-10\sqrt{33}}{-20}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-30)+10\sqrt{33}}{2*-10}=\frac{30+10\sqrt{33}}{-20}
$