Show that x = - 2 is a solution of 3x2 + 13x + 14 = 0.
If x = - 2 is a solution then it must satisfy the equation
3x2 + 13x + 14 = 0
LHS = 3x2 + 13x + 14
= 3( - 2)2 + 13( - 2) + 14
= 12 - 26 + 14 = 26 - 26 = 0 = RHS
Thus x = - 2 is a solution of the equation