Question

Solve the system of Equation (x,y)
- 4x + y = 9
x – 3y = -6

Answer 1

`(-(21)/(11),(15)/(11))`

Explanation:

Given:

`- 4x+y =9\\ x-3y = -6`

Express
`y` in terms
`x` of using the first equation.

`-4x+y=9\\y=4x+9`

Now, plug in the above value in second equation and solve for
`x`.

This gives,

`x-3y = -6\\x-3(4x+9)=-6\\x-12x-27=-6\\-11x-27=-6\\-11x=-6+27\\-11x=21\\x=(21)/(-11)=-(21)/(11)`

Now, plug in
`x` value and solve for
`y`. This gives,

`y=4x+9=4(-(21)/(11))+9=-(84)/(11)+(99)/(11)=(-84+99)/(11)=(15)/(11)`

Therefore, the solution is
`(-(21)/(11),(15)/(11))`