Use the FTC 1 to find the area of the region under the graph of the function

Question

f(x)= 8x-x^2 on [0,8].

I got 244/3 but the answer key says 256/3.

Answer 1

∫[0,8] 8x-x^2 dx
= 4x^2 - 1/3 x^3 [0,8]
= 4*8^2 - 1/3 * 8^3
= 256 - 512/3
= (768-512)/3
= 256/3

Maybe you should have shown your work.