Solving Linear Systems by Elimination

Edit: Sorry, just noticed it's in the wrong Categorie.

Hello, I did all this last year, but didn't memorize it (Doh) Now when I look back, I dont know what to do ... I would be greatful If anyone could answer the following questions. Seeing the solution might help me understand the other questions.

- Solve the following linear systems of equations using substitution.

- y = 3x + 5

y = 2x + 4 - 2x + y = 7

4x - y = 23

- Solve the following linear systems using elimination. Check your solutions.

- 3x - 2y = 18

x + y = 16 - 5x + 2y = 10

3x - 4y = -46

- A barnyard has cows and chickens. There are 34 heads and 86 legs. If w represents the number of cows and k represents the number of chickens:

- Write a linear system of equations to model this situation.
- Solve the linear system to find the number of cows and the number of chickens in the barnyard.
- Verify your solution by providing a graphical solution. You can use a spreadsheet or Geometer's Sketchpad.

Sincerely,

Serialkisser