I'm doing something wrong while solving it and I am not sure where it went wrong.

∫^{6}_0 (4x^2+2x+4)dx

Find the Riemann sum for this integral using right endpoints and n=3.
R3=

Find the Riemann sum for this same integral, using left endpoints and n=3.
L3=

so, show us your work, and we can tell you what happened ...