3(-x)+x-x(-x)=10+x

Solution for 3(-x)+x-x(-x)=10+x equation:

3(-x)+x-x(-x)=10+x

We move all terms to the left:

3(-x)+x-x(-x)-(10+x)=0

We add all the numbers together, and all the variables

3(-1x)+x-x(-1x)-(x+10)=0

We add all the numbers together, and all the variables

x+3(-1x)-x(-1x)-(x+10)=0

We multiply parentheses

1x^2+x-3x-(x+10)=0

We get rid of parentheses

1x^2+x-3x-x-10=0

We add all the numbers together, and all the variables

x^2-3x-10=0

a = 1; b = -3; c = -10;
Δ = b2-4ac
Δ = -32-4·1·(-10)
Δ = 49
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{49}=7$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-3)-7}{2*1}=\frac{-4}{2}
=-2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-3)+7}{2*1}=\frac{10}{2}
=5
$