(2b-3)(4b+10)=0

Solution for (2b-3)(4b+10)=0 equation:

(2b-3)(4b+10)=0

We multiply parentheses ..

(+8b^2+20b-12b-30)=0

We get rid of parentheses

8b^2+20b-12b-30=0

We add all the numbers together, and all the variables

8b^2+8b-30=0

a = 8; b = 8; c = -30;
Δ = b2-4ac
Δ = 82-4·8·(-30)
Δ = 1024
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1024}=32$
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(8)-32}{2*8}=\frac{-40}{16}
=-2+1/2
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(8)+32}{2*8}=\frac{24}{16}
=1+1/2
$