1/30x+1/40x=35

Solution for 1/30x+1/40x=35 equation:

1/30x+1/40x=35

We move all terms to the left:

1/30x+1/40x-(35)=0


Domain of the equation: 30x!=0

x!=0/30

x!=0

x∈R



Domain of the equation: 40x!=0

x!=0/40

x!=0

x∈R


We calculate fractions


40x/1200x^2+30x/1200x^2-35=0

We multiply all the terms by the denominator


40x+30x-35*1200x^2=0

We add all the numbers together, and all the variables

70x-35*1200x^2=0

Wy multiply elements

-42000x^2+70x=0

a = -42000; b = 70; c = 0;
Δ = b2-4ac
Δ = 702-4·(-42000)·0
Δ = 4900
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{4900}=70$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(70)-70}{2*-42000}=\frac{-140}{-84000}
=1/600
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(70)+70}{2*-42000}=\frac{0}{-84000}
=0
$