Solving Inequalities Using Addition or Subtraction.

4.2 - Solving Inequalities Using Addition or Subtraction.

By Shannon Bowen

Members of the Boy Scouts must be LESS than 18 years old. In 4 years, your friend will still be eligible to be a scout.

Multiple Choice

Members of the Boy Scouts must be LESS THAN 18 years old. In 4 years, your friend will still be eligible to be a scout.

Which of the following represents this situation?

• $$x+4>18$$  

• $$x+4<18$$  

• $$x+4\ge18$$  

• $$x+4\le18$$  

x + 4 < 18

How would we graph this?

Supercooling is ths process of lowering the temp. of a liquid or a gas below its freezing point without it becoming a solid. Water can to supercooled to 86° below its freezing point (32°) and still not freeze.

Multiple Choice

Water can to supercooled to 86° below its freezing point (32°) and still not freeze.

Which of the following represents the situation?

• $$x-32>-86$$  

• $$x-32<-86$$  

• $$x-32\ge-86$$  

• $$x-32\le-86$$  

x -32 ≧ -86

How would we graph this?

Fill in the Blanks

Solve: x + 4 = 18

x + 4 < 18

How would we graph this?

x - 32 ≧ -86

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If this were an equation instead of an inequality, we would write it as x -32 = -86.

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On the next slide, solve for x. (your answer should be in the form of x = ​)

Fill in the Blanks

Solve: $x-32=-86$  

The temperature at a weather station in Asia is MORE THAN 150°​F greater than the record low in Asia.

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Lets write an inequality that represents the situation.

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Fill in the Blanks

Solve: $x-150>-90$  

x > 60

How would we graph this?

The temperature at a research station in Antarctica is AT LEAST 80° greater than the record low in Antarctica.

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Lets write an inequality that represents the situation.

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Fill in the Blanks

Solve: $x-80\ge-129$  

x ≥-49

How would we graph this?