1/2x+x+18=90

Solution for 1/2x+x+18=90 equation:

1/2x+x+18=90

We move all terms to the left:

1/2x+x+18-(90)=0


Domain of the equation: 2x!=0

x!=0/2

x!=0

x∈R


We add all the numbers together, and all the variables

x+1/2x-72=0

We multiply all the terms by the denominator


x*2x-72*2x+1=0

Wy multiply elements

2x^2-144x+1=0

a = 2; b = -144; c = +1;
Δ = b2-4ac
Δ = -1442-4·2·1
Δ = 20728
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:

$\sqrt{\Delta}=\sqrt{20728}=\sqrt{4*5182}=\sqrt{4}*\sqrt{5182}=2\sqrt{5182}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-144)-2\sqrt{5182}}{2*2}=\frac{144-2\sqrt{5182}}{4}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-144)+2\sqrt{5182}}{2*2}=\frac{144+2\sqrt{5182}}{4}
$