Unit 1

1. Unit 1 Solving system of equations

2. System of equations • Define: system of equations- a set of two or more equations • Define: solution of a system- ordered pair(s) that make all the equations true. • Key concept: the solution to a system is where the graphs intersect. Lines are Parallel No solution Lines coincide Infinitely many solutions Lines intersect 1 solution

3. Solve by Substitution

4. Solve by Elimination Would it change the solution if we solved by eliminating the x instead of the y?

5. System word problem • Mr. Smith bought 2 lbs of jelly and 3 lbs of peanut butter. He paid $26.35. Mrs. Sing paid $18.35 for 1.5 lbs of jelly and 2 lbs of peanut butter. What was the price per pound of each item? 1st write two equations that model the above situation. ~Mr. Smith’s shopping trip ~Mrs. Sing’s shopping trip Then solve the system by using any method. $4.70/lb for Jelly $5.65/lb for Peanut Butter