14-x(x=7)

Solution for 14-x(x=7) equation:

14-x(x=7)

We move all terms to the left:

14-x(x-(7))=0

We multiply parentheses

-x^2+7x+14=0

We add all the numbers together, and all the variables

-1x^2+7x+14=0

a = -1; b = 7; c = +14;
Δ = b2-4ac
Δ = 72-4·(-1)·14
Δ = 105
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{-(7)-\sqrt{105}}{2*-1}=\frac{-7-\sqrt{105}}{-2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(7)+\sqrt{105}}{2*-1}=\frac{-7+\sqrt{105}}{-2}
$