9/4x+1/5x=87

Solution for 9/4x+1/5x=87 equation:

9/4x+1/5x=87

We move all terms to the left:

9/4x+1/5x-(87)=0


Domain of the equation: 4x!=0

x!=0/4

x!=0

x∈R



Domain of the equation: 5x!=0

x!=0/5

x!=0

x∈R


We calculate fractions


45x/20x^2+4x/20x^2-87=0

We multiply all the terms by the denominator


45x+4x-87*20x^2=0

We add all the numbers together, and all the variables

49x-87*20x^2=0

Wy multiply elements

-1740x^2+49x=0

a = -1740; b = 49; c = 0;
Δ = b2-4ac
Δ = 492-4·(-1740)·0
Δ = 2401
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2401}=49$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(49)-49}{2*-1740}=\frac{-98}{-3480}
=49/1740
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(49)+49}{2*-1740}=\frac{0}{-3480}
=0
$