(4b+11)(3b-7)=0

Solution for (4b+11)(3b-7)=0 equation:

(4b+11)(3b-7)=0

We multiply parentheses ..

(+12b^2-28b+33b-77)=0

We get rid of parentheses

12b^2-28b+33b-77=0

We add all the numbers together, and all the variables

12b^2+5b-77=0

a = 12; b = 5; c = -77;
Δ = b2-4ac
Δ = 52-4·12·(-77)
Δ = 3721
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{3721}=61$
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(5)-61}{2*12}=\frac{-66}{24}
=-2+3/4
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(5)+61}{2*12}=\frac{56}{24}
=2+1/3
$