-3/4y-1/7y=700

Solution for -3/4y-1/7y=700 equation:

-3/4y-1/7y=700

We move all terms to the left:

-3/4y-1/7y-(700)=0


Domain of the equation: 4y!=0

y!=0/4

y!=0

y∈R



Domain of the equation: 7y!=0

y!=0/7

y!=0

y∈R


We calculate fractions


(-21y)/28y^2+(-4y)/28y^2-700=0

We multiply all the terms by the denominator


(-21y)+(-4y)-700*28y^2=0

Wy multiply elements

-19600y^2+(-21y)+(-4y)=0

We get rid of parentheses

-19600y^2-21y-4y=0

We add all the numbers together, and all the variables

-19600y^2-25y=0

a = -19600; b = -25; c = 0;
Δ = b2-4ac
Δ = -252-4·(-19600)·0
Δ = 625
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{625}=25$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-25)-25}{2*-19600}=\frac{0}{-39200}
=0
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-25)+25}{2*-19600}=\frac{50}{-39200}
=-1/784
$