150x(200+10x)=1200

Solution for 150x(200+10x)=1200 equation:

150x(200+10x)=1200

We move all terms to the left:

150x(200+10x)-(1200)=0

We add all the numbers together, and all the variables

150x(10x+200)-1200=0

We multiply parentheses

1500x^2+30000x-1200=0

a = 1500; b = 30000; c = -1200;
Δ = b2-4ac
Δ = 300002-4·1500·(-1200)
Δ = 907200000
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{907200000}=\sqrt{12960000*70}=\sqrt{12960000}*\sqrt{70}=3600\sqrt{70}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(30000)-3600\sqrt{70}}{2*1500}=\frac{-30000-3600\sqrt{70}}{3000}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(30000)+3600\sqrt{70}}{2*1500}=\frac{-30000+3600\sqrt{70}}{3000}
$