Question

How do you solve this system of equations: `2( 4x + 5) = y + 4x and 1= - 2( x - y )`?

Answer 1

`x=-19/6` and `y=2 2/3`

Explanation:

Make one of the equations in terms of the other:

`y=2(4x+5)-4x`
`y=4x+10`

Now substitute into the other equation:

`1= -2(x-(4x+10))`
`1=-2(x-4x-10)`
`1=-2(-3x-10)`
`1=6x+20`
`-19=6x`
`x=-19/6`

Now put this value for `x` into the other equation:

`y=4(-19/6)+10`
`y=-12 2/3 +10`
`y=2 2/3`