(11b+15)(6b+10)=0

Solution for (11b+15)(6b+10)=0 equation:

(11b+15)(6b+10)=0

We multiply parentheses ..

(+66b^2+110b+90b+150)=0

We get rid of parentheses

66b^2+110b+90b+150=0

We add all the numbers together, and all the variables

66b^2+200b+150=0

a = 66; b = 200; c = +150;
Δ = b2-4ac
Δ = 2002-4·66·150
Δ = 400
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{400}=20$
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(200)-20}{2*66}=\frac{-220}{132}
=-1+2/3
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(200)+20}{2*66}=\frac{-180}{132}
=-1+4/11
$