Question

If x=3 is a solution of the equation x^2+kx+15=0, find the value of k. Hence find the other solution of the equation

Answer 1

x^2 + kx + 15 = 0
3^2 + 3k + 15 = 0
9 + 3k + 15 = 0
24 + 3k = 0
3k = -24
k = -24/ 3
k = -8