X+2/5x=91

Solution for X+2/5x=91 equation:

X+2/5X=91

We move all terms to the left:

X+2/5X-(91)=0


Domain of the equation: 5X!=0

X!=0/5

X!=0

X∈R


We multiply all the terms by the denominator


X*5X-91*5X+2=0

Wy multiply elements

5X^2-455X+2=0

a = 5; b = -455; c = +2;
Δ = b2-4ac
Δ = -4552-4·5·2
Δ = 206985
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-455)-\sqrt{206985}}{2*5}=\frac{455-\sqrt{206985}}{10}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-455)+\sqrt{206985}}{2*5}=\frac{455+\sqrt{206985}}{10}
$