105/7y+105/5y=12

Solution for 105/7y+105/5y=12 equation:

105/7y+105/5y=12

We move all terms to the left:

105/7y+105/5y-(12)=0


Domain of the equation: 7y!=0

y!=0/7

y!=0

y∈R



Domain of the equation: 5y!=0

y!=0/5

y!=0

y∈R


We calculate fractions


525y/35y^2+735y/35y^2-12=0

We multiply all the terms by the denominator


525y+735y-12*35y^2=0

We add all the numbers together, and all the variables

1260y-12*35y^2=0

Wy multiply elements

-420y^2+1260y=0

a = -420; b = 1260; c = 0;
Δ = b2-4ac
Δ = 12602-4·(-420)·0
Δ = 1587600
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1587600}=1260$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(1260)-1260}{2*-420}=\frac{-2520}{-840}
=+3
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(1260)+1260}{2*-420}=\frac{0}{-840}
=0
$