MATH grade 12
posted by rani on .
Determine the values of a M and N , so that the polynomial 2x^3+mx^2+nx3 and X^33mx^2+2nx+4 are both divisible by x2.
I am so lost, i do not know how to start this problem! please help i have a test soon!

Just change the variable x with the value x = 2. So, we get:
f(x) = 2x^3 + mx^2 + nx  3
f(2) = 0 = 2(8) + 4m + 2n  3
0 = 13 + 4m + 2n. ..(1)
g(x) = 3mx^2 + 2nx + 4
g(2) = 0 = 12m + 4n + 4
0 = 6m + 2n + 2. ..(2)
Using elimination and substitution for both equation (1) and (2), you'll get the values of m and n