-3x(2x-7)+4x=15

Solution for -3x(2x-7)+4x=15 equation:

-3x(2x-7)+4x=15

We move all terms to the left:

-3x(2x-7)+4x-(15)=0

We add all the numbers together, and all the variables

4x-3x(2x-7)-15=0

We multiply parentheses

-6x^2+4x+21x-15=0

We add all the numbers together, and all the variables

-6x^2+25x-15=0

a = -6; b = 25; c = -15;
Δ = b2-4ac
Δ = 252-4·(-6)·(-15)
Δ = 265
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(25)-\sqrt{265}}{2*-6}=\frac{-25-\sqrt{265}}{-12}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(25)+\sqrt{265}}{2*-6}=\frac{-25+\sqrt{265}}{-12}
$