Is 51 a composite number

yes thats correct
Omg yes kid! and here is why.. u still haven't answered my numba 9 question and I've responded to your factors and standard form of equations.

Here is the answer you seek: Using the divisibility test for 3, we see that 51 is divisible by 3 because the sum of the digits 5 and 1 is divisible by 3. Because 51 has more than two factors, it is composite.

51 = 3 x 17.