-25=x(8.33-3.5x)

Solution for -25=x(8.33-3.5x) equation:

-25=x(8.33-3.5x)

We move all terms to the left:

-25-(x(8.33-3.5x))=0

We add all the numbers together, and all the variables

-(x(-3.5x+8.33))-25=0


We calculate terms in parentheses: -(x(-3.5x+8.33)), so:

x(-3.5x+8.33)

We multiply parentheses

-3x^2+8.33x

Back to the equation:

-(-3x^2+8.33x)


We get rid of parentheses

3x^2-8.33x-25=0

a = 3; b = -8.33; c = -25;
Δ = b2-4ac
Δ = -8.332-4·3·(-25)
Δ = 369.3889
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{-(-8.33)-\sqrt{369.3889}}{2*3}=\frac{8.33-\sqrt{369.3889}}{6}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-8.33)+\sqrt{369.3889}}{2*3}=\frac{8.33+\sqrt{369.3889}}{6}
$