7x(2x+3)=30x

Solution for 7x(2x+3)=30x equation:

7x(2x+3)=30x

We move all terms to the left:

7x(2x+3)-(30x)=0

We add all the numbers together, and all the variables

-30x+7x(2x+3)=0

We multiply parentheses

14x^2-30x+21x=0

We add all the numbers together, and all the variables

14x^2-9x=0

a = 14; b = -9; c = 0;
Δ = b2-4ac
Δ = -92-4·14·0
Δ = 81
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{81}=9$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-9)-9}{2*14}=\frac{0}{28}
=0
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-9)+9}{2*14}=\frac{18}{28}
=9/14
$