(1-3x)(3x+11)=0

Solution for (1-3x)(3x+11)=0 equation:

(1-3x)(3x+11)=0

We add all the numbers together, and all the variables

(-3x+1)(3x+11)=0

We multiply parentheses ..

(-9x^2-33x+3x+11)=0

We get rid of parentheses

-9x^2-33x+3x+11=0

We add all the numbers together, and all the variables

-9x^2-30x+11=0

a = -9; b = -30; c = +11;
Δ = b2-4ac
Δ = -302-4·(-9)·11
Δ = 1296
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1296}=36$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-30)-36}{2*-9}=\frac{-6}{-18}
=1/3
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-30)+36}{2*-9}=\frac{66}{-18}
=-3+2/3
$