G7.1 Let $M=\frac{78^{3}+22^{3}}{78^{2}-78 \times 22+22^{2}}$. Find $M$.
Similar questions: 1984 FG6.1
$$
\begin{aligned}
M & =\frac{78^{3}+22^{3}}{78^{2}-78 \times 22+22^{2}} \\
& =\frac{(78+22)\left(78^{2}-78 \times 22+22^{2}\right)}{78^{2}-78 \times 22+22^{2}} \\
& =100
\end{aligned}
$$