When presented with two equations with two variables, evaluate the first equation in terms of the variable you're not solving for then insert that value into the second equation. For example, if you have x and y as variables and you're solving for x, evaluate one equation in terms of y and insert that value into the second equation then solve it for x.

Find the value of a:

-8a + y = -3

4a - 7y = -7

\(\frac{7}{13}\) | |

-3\(\frac{5}{8}\) | |

-\(\frac{2}{13}\) | |

1\(\frac{7}{9}\) |