Question

For what values of x is x2-36=5x true? A. -9 and -4 B.-4 and 9 C.4 and -9 D.9 and 4

Answer 1

x²-36=5x

x²-5x-36=0

b²-4ac = (-5)²-4(1*-36)= 169

Δ is strictly positive, the equation x²−5x−36=0 admits two solutions

(-b-√Δ)/2a =(5-13)/2 =-8/2=-4

(-b+√Δ)/2a =(5+13)/2 = 9

values of x : -4, 9

Explanation: