Y=x^2-18x+17

Solution for Y=x^2-18x+17 equation:

=Y^2-18Y+17

We move all terms to the left:

-(Y^2-18Y+17)=0

We get rid of parentheses

-Y^2+18Y-17=0

We add all the numbers together, and all the variables

-1Y^2+18Y-17=0

a = -1; b = 18; c = -17;
Δ = b2-4ac
Δ = 182-4·(-1)·(-17)
Δ = 256
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$Y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$Y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{256}=16$
$Y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(18)-16}{2*-1}=\frac{-34}{-2}
=+17
$
$Y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(18)+16}{2*-1}=\frac{-2}{-2}
=1
$