4a^2=140+8a

Solution for 4a^2=140+8a equation:

4a^2=140+8a

We move all terms to the left:

4a^2-(140+8a)=0

We add all the numbers together, and all the variables

4a^2-(8a+140)=0

We get rid of parentheses

4a^2-8a-140=0

a = 4; b = -8; c = -140;
Δ = b2-4ac
Δ = -82-4·4·(-140)
Δ = 2304
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2304}=48$
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-8)-48}{2*4}=\frac{-40}{8}
=-5
$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-8)+48}{2*4}=\frac{56}{8}
=7
$