16-x(x=5)

Solution for 16-x(x=5) equation:

16-x(x=5)

We move all terms to the left:

16-x(x-(5))=0

We multiply parentheses

-x^2+5x+16=0

We add all the numbers together, and all the variables

-1x^2+5x+16=0

a = -1; b = 5; c = +16;
Δ = b2-4ac
Δ = 52-4·(-1)·16
Δ = 89
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{-(5)-\sqrt{89}}{2*-1}=\frac{-5-\sqrt{89}}{-2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(5)+\sqrt{89}}{2*-1}=\frac{-5+\sqrt{89}}{-2}
$