Question

How do you solve `y = (2/3)x – 1` and `y = -x + 4` using substitution?

Answer 1

`x=3, y=1.`

Explanation:

We substitute the value of y from first eqn. into the second eqn., to get,
`(2/3)x-1=-x+4.`
`:.(2/3)x+x=4+1.`
`:. (2x+3x)/3=5.`
`:.5x/3=5`
`:. x=5*(3/5)=3.`

To get y, we use the second eqn.
`y=-x+4=-3+4=1.`

The soln. is `x=3, y=1.`