3x+4=3/5x+7

Solution for 3x+4=3/5x+7 equation:

3x+4=3/5x+7

We move all terms to the left:

3x+4-(3/5x+7)=0


Domain of the equation: 5x+7)!=0

x∈R


We get rid of parentheses

3x-3/5x-7+4=0

We multiply all the terms by the denominator


3x*5x-7*5x+4*5x-3=0

Wy multiply elements

15x^2-35x+20x-3=0

We add all the numbers together, and all the variables

15x^2-15x-3=0

a = 15; b = -15; c = -3;
Δ = b2-4ac
Δ = -152-4·15·(-3)
Δ = 405
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:

$\sqrt{\Delta}=\sqrt{405}=\sqrt{81*5}=\sqrt{81}*\sqrt{5}=9\sqrt{5}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-15)-9\sqrt{5}}{2*15}=\frac{15-9\sqrt{5}}{30}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-15)+9\sqrt{5}}{2*15}=\frac{15+9\sqrt{5}}{30}
$