2x(18-5x)=10

Solution for 2x(18-5x)=10 equation:

2x(18-5x)=10

We move all terms to the left:

2x(18-5x)-(10)=0

We add all the numbers together, and all the variables

2x(-5x+18)-10=0

We multiply parentheses

-10x^2+36x-10=0

a = -10; b = 36; c = -10;
Δ = b2-4ac
Δ = 362-4·(-10)·(-10)
Δ = 896
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:

$\sqrt{\Delta}=\sqrt{896}=\sqrt{64*14}=\sqrt{64}*\sqrt{14}=8\sqrt{14}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(36)-8\sqrt{14}}{2*-10}=\frac{-36-8\sqrt{14}}{-20}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(36)+8\sqrt{14}}{2*-10}=\frac{-36+8\sqrt{14}}{-20}
$