Algebra II

1
Algebra II

• 3.1 Solve Linear Systems by Graphing
• HW p.156 (4, 8, 10, 12), review old graphing
  absolute value, quadratics, etc.
• Test Next week Thursday

2
How to solve linear systems graphically.

• Graph both lines in the same coordinate plane.
• Your solution is the ordered pair where the two
  lines intersect.
• What would be the solution if the lines do not
  intersect?
• What would be the solution if the lines overlap
  each other?

3
Find the solution to the system graphically.
y -3x 2 3x 2y 2
4
Find the solution to the system graphically.
2.) y 2 x -4
3.) 2x y 4 -4x - 2y -2
4.) y -1 3x y 5
5
Find the solution to the system graphically.
2x y 4 -4x - 2y -2
6
Find the solution to the system graphically.
y -1 3x y 5
7
Algebra II

• 3.2 Solve Linear Systems Algebraically
• HW 164 (28-38 even)
• Test Thursday, 4/2

8
What are the two algebraic methods of solving a
system of equations?

• Substitution
• Elimination (linear combinations)

9
Solve the system using the substitution method.

• 2x 5y -5
• x 3y 3

10
Solve the system using the elimination method.

• 3x 7y 10
• 6x 8y 8

11
Solve the system using the substitution or
elimination method.

• 1.) 4x 3y -2 2.) 3x 3y -15
• x 5y -9 5x 9y 3

3.) 3x 6y 9 4.) 12x 3y -9 -4x
7y -16 -4x y 3
12
Solve the system using the substitution or
elimination method.

• 3.) 3x 6y 9 4.) 12x 3y -9
• -4x 7y -16 -4x y 3

13

• To raise money for uniforms, your school sells
• t-shirts. Short sleeve t-shirts cost 5 each and
  are
• sold for 8 each. Long sleeve t-shirts cost the
• school 7 each and are sold for 12 each. The
• school spends a total of 2500 on t-shirts and
• sells all of them for 4200. How many short
• sleeve t-shirts are sold?

14

• p.165 55
• In one week, a music store sold 9 guitars for a
• total of 3611. Electric guitars sold for 479
  each
• and acoustic guitars sold for 339 each. How
• many type of each guitar were sold?

15
3.4 Solve the system.

• 4x 2y 3z 1
• 2x 3y 5z -14
• 6x y 4z -1