3a*4a=7a

Solution for 3a*4a=7a equation:

3a*4a=7a

We move all terms to the left:

3a*4a-(7a)=0

We add all the numbers together, and all the variables

-7a+3a*4a=0

Wy multiply elements

12a^2-7a=0

a = 12; b = -7; c = 0;
Δ = b2-4ac
Δ = -72-4·12·0
Δ = 49
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{49}=7$
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-7)-7}{2*12}=\frac{0}{24}
=0
$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-7)+7}{2*12}=\frac{14}{24}
=7/12
$