Lesson 5-2 Solving Systems by Substitution Obj: The student will be able to solve systems of linear equations in two variables by substitution HWK: p 340 8-16 even, 17

Solving Systems of Equations by Substitution Solve for one variable in at least one equation, if necessary Substitute the resulting expression into the other equation Solve that equation to get the value of the first variable Substitute that value into one of the original equations and solve Write the values from step 3 and 4 as an ordered pair (x, y) and check

Solve each system by substitution Ex 1) y = x + 3 y = 2x + 5

Ex 2) x = 2y – 4 x + 8y = 16

Ex 3) 2x + y = -4 x + y = -7

Ex 4) 4y – 5x = 9 x – 4y = 11

Ex 5) One high speed Internet provider has a $50 setup fee and costs $30 per month. Another provider has no setup fee and costs $40 per month. In how many months will both providers cost the same? What will the cost be? If you plan to cancel in 1 year, which is the cheaper provider? Explain