10(7+x)(15x-5)=0

Solution for 10(7+x)(15x-5)=0 equation:

10(7+x)(15x-5)=0

We add all the numbers together, and all the variables

10(x+7)(15x-5)=0

We multiply parentheses ..

10(+15x^2-5x+105x-35)=0

We multiply parentheses

150x^2-50x+1050x-350=0

We add all the numbers together, and all the variables

150x^2+1000x-350=0

a = 150; b = 1000; c = -350;
Δ = b2-4ac
Δ = 10002-4·150·(-350)
Δ = 1210000
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1210000}=1100$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(1000)-1100}{2*150}=\frac{-2100}{300}
=-7
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(1000)+1100}{2*150}=\frac{100}{300}
=1/3
$