• In the next part of this section, you will have to decide which method would be best to solve the linear system.

• Graphing• Substitution• Linear Combinations (elimination)

• Graphing = a useful method for approximating a solution, checking the reasonableness of a solution, and providing a visual model.

• Section 7-1

• Substitution = a useful method when one of the variables has a coefficient of 1 or -1.

• Section 7-2

• Linear Combinations = a useful method when none of the variables has a coefficient of 1 or -1, but opposite coefficients.

• Section 7-3

Which of the three? Why?

• x + y = 300 x + 3y = 18

• 3x + 5y = 25 2x – 6y = 12

• y = 3x – 6 y = 2x + 5

• A toy maker produces wooden trains and wooden airplanes. Each train requires 3 ounces of paint and each airplane requires 5 ounces of paint. The toy maker has a gallon of paint (64 ounces). If he want to use it to paint 14 toys, how many of each can he paint?

• 3 trains and 11 airplanes

• A health food store mixes granola that costs them $4 per pound and raisins that cost them $2 per pound together to make 25 pounds of raisin granola. How many pounds of raisins should they include if they want the mixture to cost them a total of $80?

• 10 pounds

Do P. 455 21- 26 any method- you choose – show

work!!!

BUT – use at least two different methods(Note: 22-23 fractions in the ordered pair)

33, 37, 40