How do you solve x(x-9)+20=0?

1 Answer
May 13, 2016

Develop the equation

x^2-9x+20=0

Your equation is of the form

ax^2-bx+c=0

Find the discriminant (Delta)

Delta = b^2-4ac

Delta = (-9)^2-4*20= 1

Delta is greater than zero, this means two real roots exist.

x'= (-b+sqrt(Delta))/(2a)= (-(-9)+ sqrt(1))/2 =5
x''= (-b-sqrt(Delta))/(2a)= (-(-9)- sqrt(1))/2 =4