35=5(7+2x)x=

Solution for 35=5(7+2x)x= equation:

35=5(7+2x)x=

We move all terms to the left:

35-(5(7+2x)x)=0

We add all the numbers together, and all the variables

-(5(2x+7)x)+35=0


We calculate terms in parentheses: -(5(2x+7)x), so:

5(2x+7)x

We multiply parentheses

10x^2+35x

Back to the equation:

-(10x^2+35x)


We get rid of parentheses

-10x^2-35x+35=0

a = -10; b = -35; c = +35;
Δ = b2-4ac
Δ = -352-4·(-10)·35
Δ = 2625
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:

$\sqrt{\Delta}=\sqrt{2625}=\sqrt{25*105}=\sqrt{25}*\sqrt{105}=5\sqrt{105}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-35)-5\sqrt{105}}{2*-10}=\frac{35-5\sqrt{105}}{-20}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-35)+5\sqrt{105}}{2*-10}=\frac{35+5\sqrt{105}}{-20}
$