Question

How do you solve the system y=x-1 and x+y =3?

Answer 1

Since only one of the variables is defined, we can use the substitution method so first, substitute for y
`x+(x-1)=3`

Then, combine like terms and solve for x
`2x-1=3`
`x=2`

Now that we know what x is, we can substitute for x in the other equation to find y
`y=2-1`
`y=1`

Now that we know what both x and y are, we can substitute for the variables
`1=2-1` (correct)
`2+1=3` (correct)

We can now conclude the answer
`(2,1)`