Intermediate Algebra/Writing Linear Equations

Linear equations have two variables: x and y.

Examples

y = 5 + 7x

y = 2 − 4x + 4

y = 7 / 2 − 4x

If one were doing a walkathon and wanted to raise $5 for every mile walked, an equation for the total money raised, y as a function of the number of miles walked, x would be y = 5x. Would donors, however, promise to not only pay $5 per mile but give an additional $30 just for taking part, the equation would be y = 5x + 30. Note that this example is limited as negative miles don't make sense, but the line defined by the equation is infinite in either direction.