1. Algebra 1
No trumpets sound when the important decisions of our life are made. Destiny is made known silently.
Agnes DeMille
Today:
7.2 Assignment
7.2 Check Up
7.3 Instruction
Practice

2. Algebra 1
No trumpets sound when the important decisions of our life are made. Destiny is made known silently.
Agnes DeMille
Assignment:
7.2 p408 #6-12 evens, odd, 42, 43
C5 Progress Report

3. 7.2 Check Up Solve systems by substitution. Solve systems by graphing.
(-4, 3) 1 2 3 4 5 6 7 8 9 10 -6 -4 -2 -8
(5, 2)
Solve systems by graphing.
(-2, -2)

4. 7.3 Solve a Linear System by Linear Combination Objectives:
Find a solution to linear systems by Linear Combination.
Solve a system from the Real World.
Vocabulary:
none

5. 7.3 Solving Compound Inequalities (4, 0)
We need to change 2 equations with 2 variables to 1 equation with 1 variable.
(4, 0)

6. Example 1 (2, 3) Writing Compound Inequalities
Solve the system by liner combination.
Solve a System by Linear Combination
Put equations into standard form.
No opposites? - multiply equation(s) to make some.
Add equations.
Solve for the remaining variable.
Substitute this answer into one of the equations.
Solve this new equation.
Clearly state your answer.
Check the answer.
(2, 3)

7. Example 1 (3, -1) Writing Compound Inequalities
Solve the system by liner combination.
Solve a System by Linear Combination
Put equations into standard form.
No opposites? - multiply equation(s) to make some.
Add equations.
Solve for the remaining variable.
Substitute this answer into one of the equations.
Solve this new equation.
Clearly state your answer.
Check the answer.
(3, -1)

8. Example 1 (-2, 3) Writing Compound Inequalities
Solve the system by liner combination.
Solve a System by Linear Combination
Put equations into standard form.
No opposites? - multiply equation(s) to make some.
Add equations.
Solve for the remaining variable.
Substitute this answer into one of the equations.
Solve this new equation.
Clearly state your answer.
Check the answer.
(-2, 3)

9. Example 1 (4, 1) Writing Compound Inequalities
Solve the system by liner combination.
Solve a System by Linear Combination
Put equations into standard form.
No opposites? - multiply equation(s) to make some.
Add equations.
Solve for the remaining variable.
Substitute this answer into one of the equations.
Solve this new equation.
Clearly state your answer.
Check the answer.
(4, 1)

10. Example 1 (0, 4) Writing Compound Inequalities
Solve the system by liner combination.
Solve a System by Linear Combination
Put equations into standard form.
No opposites? - multiply equation(s) to make some.
Add equations.
Solve for the remaining variable.
Substitute this answer into one of the equations.
Solve this new equation.
Clearly state your answer.
Check the answer.
(0, 4)

11. Example 1 (2, -2) Writing Compound Inequalities
Solve the system by liner combination.
Solve a System by Linear Combination
Put equations into standard form.
No opposites? - multiply equation(s) to make some.
Add equations.
Solve for the remaining variable.
Substitute this answer into one of the equations.
Solve this new equation.
Clearly state your answer.
Check the answer.
(2, -2)

12. Example 1 (1, 5) Writing Compound Inequalities
Solve the system by liner combination.
Solve a System by Linear Combination
Put equations into standard form.
No opposites? - multiply equation(s) to make some.
Add equations.
Solve for the remaining variable.
Substitute this answer into one of the equations.
Solve this new equation.
Clearly state your answer.
Check the answer.
(1, 5)

13. Example 1 (6, -8) Writing Compound Inequalities
Solve the system by liner combination.
Solve a System by Linear Combination
Put equations into standard form.
No opposites? - multiply equation(s) to make some.
Add equations.
Solve for the remaining variable.
Substitute this answer into one of the equations.
Solve this new equation.
Clearly state your answer.
Check the answer.
(6, -8)

14. Example 1 (2, ½) Writing Compound Inequalities
Solve the system by liner combination.
Solve a System by Linear Combination
Put equations into standard form.
No opposites? - multiply equation(s) to make some.
Add equations.
Solve for the remaining variable.
Substitute this answer into one of the equations.
Solve this new equation.
Clearly state your answer.
Check the answer.
(2, ½)

15. Example 1 (-.5, 1.5) Writing Compound Inequalities
Solve the system by liner combination.
Solve a System by Linear Combination
Put equations into standard form.
No opposites? - multiply equation(s) to make some.
Add equations.
Solve for the remaining variable.
Substitute this answer into one of the equations.
Solve this new equation.
Clearly state your answer.
Check the answer.
(-.5, 1.5)

16. 56 compasses 24 protractors
Example 2
Real Life Inequalities
In the beginning of the year I sell in my geometry classes 80 compasses and protractors combined. A compass costs $2 and a protractor is $.50, how many of each did I sell if I took in $124?
56 compasses 24 protractors

17. Example 2 Real Life Inequalities
A gold crown, suspected of containing some silver, was found to have a mass of 714 grams and a volume of 46 cubic centimeters. The density of gold is about 19 grams pre cubic centimeter. The density of silver is about 10.5 grams per cubic centimeter. How much silver is in this crown?
g + s = 46 and 10g + 1.5s = 714
18.8 cm3

18. 7.3 Solve a Linear System by Linear Combination Graphing Substitution
Solving a system of linear equations.
Graphing
Substitution
Linear Combination

19. 7.3 Assignment: 7.3 p414 #1-7,… Solve a System by Linear Combination
Put equations into standard form.
No opposites? - multiply equation(s) to make some.
Add equations.
Solve for the remaining variable.
Substitute this answer into one of the equations.
Solve this new equation.
Clearly state your answer.
Check the answer.

20. Algebra 1
No trumpets sound when the important decisions of our life are made. Destiny is made known silently.
Agnes DeMille
Assignment:
7.3 p414 #1-7, 9-39 x3’s, p409 #44
C5 Progress Report
Chapter Quiz on Wednesday