Lesson 10-6 solving inequalities by adding or subtracting

SWBAT solve inequalities through addition and subtraction

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Agenda

• 5 minute check

• Get back the reading to learn math worksheet, place in notes section

• Ms Swartz checks that you did the homework

• You check your homework

• Lesson

• homework

Remember

• 2 warnings now = note home.

NEW TIMER GOAL: 15 seconds or under (INEQUALITY, YAY) means 1 bonus point added to the quiz. 10 seconds or under means 2 bonus points added to the quiz. 5 seconds or under means 3 bonus points added to the quiz. If you get any warnings or a note home you don’t get bonus points.

To solve inequalities using addition and subtraction

• Its just like solving equations with addition and subtraction

• You want to get the variable by itself

• What you do to one side of the inequality, you do to the other side

• The inequality sign stays the same

• The only thing that is different is checking the inequality.

Example 1 Solve an Inequality Using Addition

Example 2 Solve an Inequality Using Subtraction

Example 3 Graph the Solutions of an Inequality

Example 4 Use an Inequality to Solve a Problem

Write the inequality.

Simplify.

Add 4 to each side.

Replace n with a number greater than 10, such as 11.

Write the inequality.Check

The statement is true.

Answer: Any number greater than 10 will make the statement true, so the solution is

Check your solution.Solve

Check your solution.

Answer:

Solve

Check your solution.Write the inequality.

Simplify.

Subtract 8 from each side.

Check Replace x in the original inequality with –15 and then with a number less than –15.

Answer: The solution is

Solve

Check your solution.

Answer:

Solve

The solution is Graph the solution.

Then graph the solution on a

number line.

Solve

Answer:

Place an open circle at Draw a line and an arrow to the left.

Answer:

Solve Then graph the solution on a

number line.

TOWING COMPANY A pickup truck is towing a trailer that weighs 3,525 pounds. The maximum towing capacity of the truck is 4,700 pounds. Determine how much more weight can be added to the trailer and still be towed by the truck.

Words

Variable

Inequality

The phrase maximum capacity means less than or equal to. So, the current weight being towed plus any more weight must be less than or equal to 4,700 pounds.

3,525 + w 4,700

current weight plus

weight added

must be less than or

equal to4,700

pounds

Answer: Up to 1,175 more pounds can be added to the trailer.

Write the inequality.

Simplify.

Subtract 3,525 from each side.

SPORTS A weightlifter can lift up to 375 pounds. He is currently lifting 255 pounds. Determine how much more weight can be added and still be lifted by the weightlifter.

Answer: Up to 120 more pounds can be added.

Homework

• SGI workbook page 79, lesson 10-6