Let a,b, and c be distinct real numbers such that a3+6a=b3+6b=c3+6c. Find a3+b3+c3.
By inspection:
13+61=7
23+62=7
Unfortunately 33+63≠7
However (−3)3+6−3=7
I'll leave you to finish.
tysm!!! the answer is -18 for anyone wondering :)