(8x+3)(7-2x)=0

Solution for (8x+3)(7-2x)=0 equation:

(8x+3)(7-2x)=0

We add all the numbers together, and all the variables

(8x+3)(-2x+7)=0

We multiply parentheses ..

(-16x^2+56x-6x+21)=0

We get rid of parentheses

-16x^2+56x-6x+21=0

We add all the numbers together, and all the variables

-16x^2+50x+21=0

a = -16; b = 50; c = +21;
Δ = b2-4ac
Δ = 502-4·(-16)·21
Δ = 3844
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{3844}=62$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(50)-62}{2*-16}=\frac{-112}{-32}
=3+1/2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(50)+62}{2*-16}=\frac{12}{-32}
=-3/8
$