Which Method Should Be Used to Solve the System? Explain $$\begin{aligned}- 7 x ^ { 2 } + y ^ { 2 } & = 64 \\- 5 x ^ { 2 } + 4 y ^ { 2 } & = 100\end{aligned}$$

Essay

Which method should be used to solve the system? Explain your answer, including a description of the first step.
- $$\begin{aligned}- 7 x ^ { 2 } + y ^ { 2 } & = 64 \\- 5 x ^ { 2 } + 4 y ^ { 2 } & = 100\end{aligned}$$