3(x-1)(x+4)=198

Solution for 3(x-1)(x+4)=198 equation:

3(x-1)(x+4)=198

We move all terms to the left:

3(x-1)(x+4)-(198)=0

We multiply parentheses ..

3(+x^2+4x-1x-4)-198=0

We multiply parentheses

3x^2+12x-3x-12-198=0

We add all the numbers together, and all the variables

3x^2+9x-210=0

a = 3; b = 9; c = -210;
Δ = b2-4ac
Δ = 92-4·3·(-210)
Δ = 2601
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2601}=51$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(9)-51}{2*3}=\frac{-60}{6}
=-10
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(9)+51}{2*3}=\frac{42}{6}
=7
$