100+(17-y)=y^2

Solution for 100+(17-y)=y^2 equation:

100+(17-y)=y^2

We move all terms to the left:

100+(17-y)-(y^2)=0

determiningTheFunctionDomain
-y^2+(17-y)+100=0

We add all the numbers together, and all the variables

-y^2+(-1y+17)+100=0

We add all the numbers together, and all the variables

-1y^2+(-1y+17)+100=0

We get rid of parentheses

-1y^2-1y+17+100=0

We add all the numbers together, and all the variables

-1y^2-1y+117=0

a = -1; b = -1; c = +117;
Δ = b2-4ac
Δ = -12-4·(-1)·117
Δ = 469
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-1)-\sqrt{469}}{2*-1}=\frac{1-\sqrt{469}}{-2}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1)+\sqrt{469}}{2*-1}=\frac{1+\sqrt{469}}{-2}
$