Part 1: Systems of Equations & Applications

In this section, systems of equations and applications of them are studied.  There are two ways to solve a system of equations in two variables: substitution and elimination.  We can apply these methods to application problems as well.

You can find the supplement here.

Here are some practice problems.  I will provide solutions to these later.

1)  4x - 9y = 24
     5x + 3y = 17


2)  8x + 20y = 9
     8x + 20y = 10


3)  Jim and Bob are hosting a huge cookout.  Jim buys 100 pounds of ribs and 20 pounds of steaks and spends $700.  Bob buys 50 pounds of ribs and 40 pounds of steaks and spends $1,200.  How much did they pay per pound for ribs?  How much did they pay per pound for steak?

Answers:

2) No solution.  Since 8x + 20y = 9 and 8x + 20y = 10, it follows that 9 = 10 which is absurd.