Question

How do solve the following linear system?: `-9x + 6y = -2 , 11x + 3y + 7 = 0`?

Answer 1

1) multiply the second equation by 2
`22x + 6y +14=0`

2) set the first equation equal to `0` then make both equations equal to each other
`22x+6y+14=-9x+6y+2`

3) move everything to one side and sum it up
`31x+12=0`
`31x=-12`
`x=-12/31`

4) insert `x` into the first equation and you get
`(-9*(-12))/31+6y=-2`
`6y=((-2*31)-9*12)/31`
`y=((-2*31)-9*12)/(6*31)`
`y=(-31-54)/93=-85/93`