Solve the quadratic equation x2−9x+20=0.
5,1
4,5
-5,-1
-2,3
Given: x2−9x+20=0, x2−4x−5x+20=x(x−4)−5(x−4)⇒(x−4)(x−5)=0⇒(x−4)=0 or (x−5)=0⇒x=4,5 The roots of the equation x2−9x+20=0 are 4,5.