Question

Solve using Elimination or Elimination with Multiplication.
x - y = 3 and x + y = 7

Answer 1

Add the equations. 2x = 10 -> x = 5; 5 - y = 3 -> y = 2.

You can use Gaussian elimination to solve any problem of this form: http://www.purplemath.com/modules/systlin6.htm

Answer 2

x-y=3
x+y=7 +
----------------
2x=10
x=5

5-y=3
y=2