25=5(x+3)7x

Solution for 25=5(x+3)7x equation:

25=5(x+3)7x

We move all terms to the left:

25-(5(x+3)7x)=0


We calculate terms in parentheses: -(5(x+3)7x), so:

5(x+3)7x

We multiply parentheses

35x^2+105x

Back to the equation:

-(35x^2+105x)


We get rid of parentheses

-35x^2-105x+25=0

a = -35; b = -105; c = +25;
Δ = b2-4ac
Δ = -1052-4·(-35)·25
Δ = 14525
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:

$\sqrt{\Delta}=\sqrt{14525}=\sqrt{25*581}=\sqrt{25}*\sqrt{581}=5\sqrt{581}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-105)-5\sqrt{581}}{2*-35}=\frac{105-5\sqrt{581}}{-70}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-105)+5\sqrt{581}}{2*-35}=\frac{105+5\sqrt{581}}{-70}
$