(10w-6)(4w+7)=0

Solution for (10w-6)(4w+7)=0 equation:

(10w-6)(4w+7)=0

We multiply parentheses ..

(+40w^2+70w-24w-42)=0

We get rid of parentheses

40w^2+70w-24w-42=0

We add all the numbers together, and all the variables

40w^2+46w-42=0

a = 40; b = 46; c = -42;
Δ = b2-4ac
Δ = 462-4·40·(-42)
Δ = 8836
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$w_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$w_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{8836}=94$
$w_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(46)-94}{2*40}=\frac{-140}{80}
=-1+3/4
$
$w_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(46)+94}{2*40}=\frac{48}{80}
=3/5
$