s+21/2s+10=31

Solution for s+21/2s+10=31 equation:

s+21/2s+10=31

We move all terms to the left:

s+21/2s+10-(31)=0


Domain of the equation: 2s!=0

s!=0/2

s!=0

s∈R


We add all the numbers together, and all the variables

s+21/2s-21=0

We multiply all the terms by the denominator


s*2s-21*2s+21=0

Wy multiply elements

2s^2-42s+21=0

a = 2; b = -42; c = +21;
Δ = b2-4ac
Δ = -422-4·2·21
Δ = 1596
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$s_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$s_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{1596}=\sqrt{4*399}=\sqrt{4}*\sqrt{399}=2\sqrt{399}$
$s_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-42)-2\sqrt{399}}{2*2}=\frac{42-2\sqrt{399}}{4}
$
$s_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-42)+2\sqrt{399}}{2*2}=\frac{42+2\sqrt{399}}{4}
$