Question

Solve the system of equations x + 7y = 5 and — 3x – 8y = 11 by
combining the equations.

Answer 1

x = -9

y = 2

Explanation:

Elimination

x + 7y = 5 | ×3 |

-3x - 8y = 11 | ×1 |

3x + 21y = 15

-3x - 8y = 11

__________+

13y = 26

y = 26/13

y = 2

Subsitution

x + 7y = 5

x + 7(2) = 5

x + 14 = 5

x = 5 - 14

x = -9