4/5x-(-1/4x)=11

Solution for 4/5x-(-1/4x)=11 equation:

4/5x-(-1/4x)=11

We move all terms to the left:

4/5x-(-1/4x)-(11)=0


Domain of the equation: 5x!=0

x!=0/5

x!=0

x∈R



Domain of the equation: 4x)!=0

x!=0/1

x!=0

x∈R


We get rid of parentheses

4/5x+1/4x-11=0

We calculate fractions


16x/20x^2+5x/20x^2-11=0

We multiply all the terms by the denominator


16x+5x-11*20x^2=0

We add all the numbers together, and all the variables

21x-11*20x^2=0

Wy multiply elements

-220x^2+21x=0

a = -220; b = 21; c = 0;
Δ = b2-4ac
Δ = 212-4·(-220)·0
Δ = 441
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{441}=21$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(21)-21}{2*-220}=\frac{-42}{-440}
=21/220
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(21)+21}{2*-220}=\frac{0}{-440}
=0
$