Find solutions to systems of two linear equations in two variables. SPI 0806.3.1

Links verified on 9/29/2014

1. Save Our Dumb Planet - [a linear equation game] Deduce correct flight path equations and then plot co-ordinates accurately to ensure your missiles hit their targets and destroy the rogue meteors heading on a collision course with Earth!
2. Systems of Linear Equations: Definitions  - page 1 of 7 from Purple Math