Question

If x = 6 is a root of the quadratic equation 3 x 2 − m x − 24 = 0 , then the value of m is

Answer 1

3x^2 - mx - 24 = 0

Placing the value of x,

3(6)^2 - m(6) - 24 = 0

3(36) - 6m - 24 =0

108 - 6m - 24=0

Transposing 108 and -24 from LHS to RHS,

-6m = 24- 108

-6m = - 84

m = -84 / -6

= 16