7x(5x+10)=4x

Solution for 7x(5x+10)=4x equation:

7x(5x+10)=4x

We move all terms to the left:

7x(5x+10)-(4x)=0

We add all the numbers together, and all the variables

-4x+7x(5x+10)=0

We multiply parentheses

35x^2-4x+70x=0

We add all the numbers together, and all the variables

35x^2+66x=0

a = 35; b = 66; c = 0;
Δ = b2-4ac
Δ = 662-4·35·0
Δ = 4356
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{4356}=66$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(66)-66}{2*35}=\frac{-132}{70}
=-1+31/35
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(66)+66}{2*35}=\frac{0}{70}
=0
$