(14b+6)(15b+10)=0

Solution for (14b+6)(15b+10)=0 equation:

(14b+6)(15b+10)=0

We multiply parentheses ..

(+210b^2+140b+90b+60)=0

We get rid of parentheses

210b^2+140b+90b+60=0

We add all the numbers together, and all the variables

210b^2+230b+60=0

a = 210; b = 230; c = +60;
Δ = b2-4ac
Δ = 2302-4·210·60
Δ = 2500
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2500}=50$
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(230)-50}{2*210}=\frac{-280}{420}
=-2/3
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(230)+50}{2*210}=\frac{-180}{420}
=-3/7
$