(-7y-6)(-3y-10)=0

Solution for (-7y-6)(-3y-10)=0 equation:

(-7y-6)(-3y-10)=0

We multiply parentheses ..

(+21y^2+70y+18y+60)=0

We get rid of parentheses

21y^2+70y+18y+60=0

We add all the numbers together, and all the variables

21y^2+88y+60=0

a = 21; b = 88; c = +60;
Δ = b2-4ac
Δ = 882-4·21·60
Δ = 2704
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2704}=52$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(88)-52}{2*21}=\frac{-140}{42}
=-3+1/3
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(88)+52}{2*21}=\frac{-36}{42}
=-6/7
$