(5h-4)(8h-7)=0

Solution for (5h-4)(8h-7)=0 equation:

(5h-4)(8h-7)=0

We multiply parentheses ..

(+40h^2-35h-32h+28)=0

We get rid of parentheses

40h^2-35h-32h+28=0

We add all the numbers together, and all the variables

40h^2-67h+28=0

a = 40; b = -67; c = +28;
Δ = b2-4ac
Δ = -672-4·40·28
Δ = 9
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$h_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$h_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{9}=3$
$h_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-67)-3}{2*40}=\frac{64}{80}
=4/5
$
$h_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-67)+3}{2*40}=\frac{70}{80}
=7/8
$