3/a+4/a=7a

Solution for 3/a+4/a=7a equation:

3/a+4/a=7a

We move all terms to the left:

3/a+4/a-(7a)=0


Domain of the equation: a!=0

a∈R


We add all the numbers together, and all the variables

-7a+3/a+4/a=0

We multiply all the terms by the denominator


-7a*a+3+4=0

We add all the numbers together, and all the variables

-7a*a+7=0

Wy multiply elements

-7a^2+7=0

a = -7; b = 0; c = +7;
Δ = b2-4ac
Δ = 02-4·(-7)·7
Δ = 196
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{196}=14$
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-14}{2*-7}=\frac{-14}{-14}
=1
$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+14}{2*-7}=\frac{14}{-14}
=-1
$