X=(2x-30)-30/2

Solution for X=(2x-30)-30/2 equation:

X=(2X-30)-30/2

We move all terms to the left:

X-((2X-30)-30/2)=0

We multiply all the terms by the denominator


X*2)-((2X-30)-30=0

Wy multiply elements

2X^2-30=0

a = 2; b = 0; c = -30;
Δ = b2-4ac
Δ = 02-4·2·(-30)
Δ = 240
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:

$\sqrt{\Delta}=\sqrt{240}=\sqrt{16*15}=\sqrt{16}*\sqrt{15}=4\sqrt{15}$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-4\sqrt{15}}{2*2}=\frac{0-4\sqrt{15}}{4}
=-\frac{4\sqrt{15}}{4}
=-\sqrt{15}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+4\sqrt{15}}{2*2}=\frac{0+4\sqrt{15}}{4}
=\frac{4\sqrt{15}}{4}
=\sqrt{15}
$