3/4x+7=2x+12

Solution for 3/4x+7=2x+12 equation:

3/4x+7=2x+12

We move all terms to the left:

3/4x+7-(2x+12)=0


Domain of the equation: 4x!=0

x!=0/4

x!=0

x∈R


We get rid of parentheses

3/4x-2x-12+7=0

We multiply all the terms by the denominator


-2x*4x-12*4x+7*4x+3=0

Wy multiply elements

-8x^2-48x+28x+3=0

We add all the numbers together, and all the variables

-8x^2-20x+3=0

a = -8; b = -20; c = +3;
Δ = b2-4ac
Δ = -202-4·(-8)·3
Δ = 496
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{496}=\sqrt{16*31}=\sqrt{16}*\sqrt{31}=4\sqrt{31}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-20)-4\sqrt{31}}{2*-8}=\frac{20-4\sqrt{31}}{-16}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-20)+4\sqrt{31}}{2*-8}=\frac{20+4\sqrt{31}}{-16}
$