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Absolute value bars act like grouping symbols. First simplify inside the absolute value bars as much as possible. Then take the absolute value of the resulting number, and continue with any operations outside the absolute value symbols.
Simplify:
For each expression, follow the order of operations. Begin inside the absolute value symbols just as with parentheses.
ⓐ | |
|9−3| | |
Simplify inside the absolute value sign. | |6| |
Take the absolute value. | 6 |
ⓑ | |
4|−2| | |
Take the absolute value. | 4⋅2 |
Multiply. | 8 |
Simplify:
For each expression, follow the order of operations. Begin inside the absolute value symbols just as with parentheses.
|8+7|−|5+6| | |
Simplify inside each absolute value sign. | |15|−|11| |
Subtract. | 4 |
Simplify:
We use the order of operations . Remember to simplify grouping symbols first, so parentheses inside absolute value symbols would be first.
Now we can translate word phrases into expressions with integers . Look for words that indicate a negative sign. For example, the word negative in “negative twenty” indicates So does the word opposite in “the opposite of
Translate each phrase into an expression with integers:
Translate each phrase into an expression with integers:
Translate each phrase into an expression with integers:
As we saw at the start of this section, negative numbers are needed to describe many real-world situations. We’ll look at some more applications of negative numbers in the next example.
Translate into an expression with integers:
Look for key phrases in each sentence. Then look for words that indicate negative signs. Don’t forget to include units of measurement described in the sentence.
ⓐ | The temperature is 12 degrees Fahrenheit below zero. |
Below zero tells us that 12 is a negative number. |
ⓑ | The football team had a gain of 3 yards. |
A gain tells us that 3 is a positive number. | yards |
ⓒ | The elevation of the Dead Sea is 1,302 feet below sea level. |
Below sea level tells us that 1,302 is a negative number. | feet |
ⓓ | A checking account is overdrawn by $40. |
Overdrawn tells us that 40 is a negative number. |
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