Question

Solve the system of equations for -2x-2y=-6 and 3x +4y=8

Answer 1

Answer: (4,-1)

Explanation:

`-2x-2y=-6\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ (divide\ both\ parts\ of \ the\ equation\ by\ 2):\\3x+4y=8\\\\-x-y=-3\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ (multiply\ both\ parts\ of \ the\ equation\ by\ 3)\\3x+4y=8\\\\-3x-3y=-9\ \ \ \ \ (1)\\3x+4y=8\ \ \ \ \ \ \ \ \ \ (2)\\\\`

Summarize equations (1) and (2):

`y=-1`

Hence,

3x+4(-1)=8

3x-4=8

3x-4+4=8+4

3x=12 (divide both parts of the equation by 3)

x=4