X2-9x+20=(x-5)

Solution for X2-9x+20=(x-5) equation:

X2-9X+20=(X-5)

We move all terms to the left:

X2-9X+20-((X-5))=0

We add all the numbers together, and all the variables

X^2-9X-((X-5))+20=0


We calculate terms in parentheses: -((X-5)), so:

(X-5)

We get rid of parentheses

X-5

Back to the equation:

-(X-5)


We get rid of parentheses

X^2-9X-X+5+20=0

We add all the numbers together, and all the variables

X^2-10X+25=0

a = 1; b = -10; c = +25;
Δ = b2-4ac
Δ = -102-4·1·25
Δ = 0
Delta is equal to zero, so there is only one solution to the equation

                              Stosujemy wzór:
$X=\frac{-b}{2a}=\frac{10}{2}=5$