algebraic equation method

You have to work out one unknown in both equations and equalize.

Example 1:

Example 2:

Exercise: solve the following systems of equations using the algebraic equation method:

Solutions: a) x = 3, y = -3; b) x = 1/4, y = 3/4; c) x = 1/3, y = -1/2; d) x = -1, y = 4