X=(y-5)(y-5)

Solution for X=(y-5)(y-5) equation:

X=(X-5)(X-5)

We move all terms to the left:

X-((X-5)(X-5))=0

We multiply parentheses ..

-((+X^2-5X-5X+25))+X=0


We calculate terms in parentheses: -((+X^2-5X-5X+25)), so:

(+X^2-5X-5X+25)

We get rid of parentheses

X^2-5X-5X+25

We add all the numbers together, and all the variables

X^2-10X+25

Back to the equation:

-(X^2-10X+25)


We add all the numbers together, and all the variables

X-(X^2-10X+25)=0

We get rid of parentheses

-X^2+X+10X-25=0

We add all the numbers together, and all the variables

-1X^2+11X-25=0

a = -1; b = 11; c = -25;
Δ = b2-4ac
Δ = 112-4·(-1)·(-25)
Δ = 21
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{-(11)-\sqrt{21}}{2*-1}=\frac{-11-\sqrt{21}}{-2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(11)+\sqrt{21}}{2*-1}=\frac{-11+\sqrt{21}}{-2}
$