Question

-4x+y+6
-5x-y=21
solve by substitution

Answer 1

x = 15/-9

y = -114/9

Explanation:

-4x + y + 6

-4x + y = -6

-5x - y = 21

-4x + y = -6

-5x - y = 21

__________+

-9x = 15

x = 15/-9

-4x + y = -6 | ×5 |

-5x - y = 21 | ×4 |

-20x + 5y = -30

-20x - 4y = 84

_____________--

9y = -114

y = -114/9