solve the system

Question

Solve the system.

 

            3x + 4y = -13

 

            5x + 6y = -19

Answer 1

Can also use elimination method:

(1) 3x + 4y = -13

(2) 5x + 6y = -19 Need to eliminate x or y. Let's mult (1) by 3 and (2) by -2 to eliminate the y's

9x + 12y = -39

-10x -12y = 38

-x = -1, so x = 1

Now you can solve for y by substituting x = 1 into either of the original equations.

Answer 2

Can use Cramer's rule

Determinants:

| 3 4 |=-2

| 5 6 |

|-13 4 |=-2

|-19 6 |

|3 -13 |=8

|5 -19 |

x = -2/-2 = 1

y = 8/-2 = -4