Answer:
k = 6
Step-by-step explanation:
(x+2) is a factor of 3x²+kx so if we solve (x+2) = 0 that will give us one of the solutions of x for 3x²+kx = 0, and then we can substitute that solution in and find the value of k.
So to find a solution, (x+2) = 0 and therefore x = -2
Now substitute x = -2 into 3x²+kx = 0
so 3(-2)²+k(-2) = 0
12 - 2k = 0
2k = 12
k = 6
