Let a and b be real numbers such that a3 +3ab2 =679 and 3a2 b + b3 = -652 Find a + b.
Thanks
Add the 2 equations up:
\(a^3+3ab^2+3a^2b+b^3=27\)\(\)
Notice that \((a+b)^3=a^3+3ab^2+3a^2b+b^3\)\(\) by the binomial theorem. Therefore, \((a+b)^3 = 27 \rightarrow \boxed{a+b=3}\)
Thank you
