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

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

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

We multiply parentheses ..

(+8x^2-6x+40x-30)=0

We get rid of parentheses

8x^2-6x+40x-30=0

We add all the numbers together, and all the variables

8x^2+34x-30=0

a = 8; b = 34; c = -30;
Δ = b2-4ac
Δ = 342-4·8·(-30)
Δ = 2116
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2116}=46$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(34)-46}{2*8}=\frac{-80}{16}
=-5
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(34)+46}{2*8}=\frac{12}{16}
=3/4
$