3x(3x+10)=-16

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

3x(3x+10)=-16

We move all terms to the left:

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

We add all the numbers together, and all the variables

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

We multiply parentheses

9x^2+30x+16=0

a = 9; b = 30; c = +16;
Δ = b2-4ac
Δ = 302-4·9·16
Δ = 324
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{324}=18$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(30)-18}{2*9}=\frac{-48}{18}
=-2+2/3
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(30)+18}{2*9}=\frac{-12}{18}
=-2/3
$