1440=5x*8x

Solution for 1440=5x*8x equation:

1440=5x*8x

We move all terms to the left:

1440-(5x*8x)=0

We add all the numbers together, and all the variables

-(+5x*8x)+1440=0

We get rid of parentheses

-5x*8x+1440=0

Wy multiply elements

-40x^2+1440=0

a = -40; b = 0; c = +1440;
Δ = b2-4ac
Δ = 02-4·(-40)·1440
Δ = 230400
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{230400}=480$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-480}{2*-40}=\frac{-480}{-80}
=+6
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+480}{2*-40}=\frac{480}{-80}
=-6
$