Today:• 7.2 Assignment• 7.2 Check Up• 7.3 Instruction• Practice

No trumpets sound when the important decisions of our life are made. Destiny is made known silently.

Agnes DeMille

Algebra 1

Algebra 1

Assignment:• 7.2 p408 #6-12

evens, 17-31 odd, 42, 43

• C5 Progress Report

No trumpets sound when the important decisions of our life are made. Destiny is made known silently.

Agnes DeMille

Algebra 1

Check Up7.2

Solve systems by substitution.

13y2x 84yx1. (-4,

3)

23y-5x112y3x-2. (5, 2)

-22yx-43xy3. (-2, -

2)

Solve systems by graphing.

1 2 3 4 5 6 7 8 9 10

123

56

4

789

10

-6-4 -2-8

-6

-2

-4

-8

Solve a Linear System by Linear Combination

7.3

Objectives:1. Find a solution to linear systems by Linear

Combination.2. Solve a system from the Real World. Vocabulary: none

Solving Compound Inequalities7.3We need to change 2 equations with 2 variables to 1 equation with 1 variable.

83y-2x

163y4x (4, 0)

Solve the system by liner combination. Solve a System by Linear

Combination

1. Put equations into standard form.

2. No opposites? - multiply equation(s) to make some.

3. Add equations.

4. Solve for the remaining variable.

5. Substitute this answer into one of the equations.

6. Solve this new equation.

7. Clearly state your answer.

8. Check the answer.

122y3x

22y4x(2, 3)

Example 1 Writing Compound Inequalities

Solve the system by liner combination. Solve a System by Linear

Combination

1. Put equations into standard form.

2. No opposites? - multiply equation(s) to make some.

3. Add equations.

4. Solve for the remaining variable.

5. Substitute this answer into one of the equations.

6. Solve this new equation.

7. Clearly state your answer.

8. Check the answer.

54y3x

72y3x(3, -1)

Example 1 Writing Compound Inequalities

Solve the system by liner combination.

193y5x-

-42y5x(-2, 3)

Solve a System by Linear Combination

1. Put equations into standard form.

2. No opposites? - multiply equation(s) to make some.

3. Add equations.

4. Solve for the remaining variable.

5. Substitute this answer into one of the equations.

6. Solve this new equation.

7. Clearly state your answer.

8. Check the answer.

Example 1 Writing Compound Inequalities

Solve the system by liner combination.

182y5x

284y6x(4, 1)

Solve a System by Linear Combination

1. Put equations into standard form.

2. No opposites? - multiply equation(s) to make some.

3. Add equations.

4. Solve for the remaining variable.

5. Substitute this answer into one of the equations.

6. Solve this new equation.

7. Clearly state your answer.

8. Check the answer.

Example 1 Writing Compound Inequalities

Solve the system by liner combination.

328y12x

123y4x(0, 4)

Solve a System by Linear Combination

1. Put equations into standard form.

2. No opposites? - multiply equation(s) to make some.

3. Add equations.

4. Solve for the remaining variable.

5. Substitute this answer into one of the equations.

6. Solve this new equation.

7. Clearly state your answer.

8. Check the answer.

Example 1 Writing Compound Inequalities

Solve the system by liner combination.

2-4x9y4x

43y5x(2, -2)

Solve a System by Linear Combination

1. Put equations into standard form.

2. No opposites? - multiply equation(s) to make some.

3. Add equations.

4. Solve for the remaining variable.

5. Substitute this answer into one of the equations.

6. Solve this new equation.

7. Clearly state your answer.

8. Check the answer.

Example 1 Writing Compound Inequalities

Solve the system by liner combination.

174y3x-

275y2x(1, 5)

Solve a System by Linear Combination

1. Put equations into standard form.

2. No opposites? - multiply equation(s) to make some.

3. Add equations.

4. Solve for the remaining variable.

5. Substitute this answer into one of the equations.

6. Solve this new equation.

7. Clearly state your answer.

8. Check the answer.

Example 1 Writing Compound Inequalities

Solve the system by liner combination.

0165y4x

123y6x(6, -8)

Solve a System by Linear Combination

1. Put equations into standard form.

2. No opposites? - multiply equation(s) to make some.

3. Add equations.

4. Solve for the remaining variable.

5. Substitute this answer into one of the equations.

6. Solve this new equation.

7. Clearly state your answer.

8. Check the answer.

Example 1 Writing Compound Inequalities

Solve the system by liner combination.

24y2x

112y5x(2, ½)

Solve a System by Linear Combination

1. Put equations into standard form.

2. No opposites? - multiply equation(s) to make some.

3. Add equations.

4. Solve for the remaining variable.

5. Substitute this answer into one of the equations.

6. Solve this new equation.

7. Clearly state your answer.

8. Check the answer.

Example 1 Writing Compound Inequalities

Solve the system by liner combination.

52y4x-

65y3x(-.5, 1.5)

Solve a System by Linear Combination

1. Put equations into standard form.

2. No opposites? - multiply equation(s) to make some.

3. Add equations.

4. Solve for the remaining variable.

5. Substitute this answer into one of the equations.

6. Solve this new equation.

7. Clearly state your answer.

8. Check the answer.

Example 1 Writing Compound 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

compasses24

protractors

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?

18.8 cm3

Example 2 Real Life Inequalities

Solving a system of linear equations.

1. Graphing2. Substitution3. Linear Combination4.

Solve a Linear System by Linear Combination

7.3

Assignment:

7.3 p414 #1-7,… 7.3

Solve a System by Linear Combination

1. Put equations into standard form.

2. No opposites? - multiply equation(s) to make some.

3. Add equations.

4. Solve for the remaining variable.

5. Substitute this answer into one of the equations.

6. Solve this new equation.

7. Clearly state your answer.

8. Check the answer.

Assignment:• 7.3 p414 #1-7, 9-

39 x3’s, p409 #44• C5 Progress

Report• Chapter 6.1-3

Quiz on Wednesday

No trumpets sound when the important decisions of our life are made. Destiny is made known silently.

Agnes DeMille

Algebra 1