Lesson 1–1
Example 1 Evaluate Algebraic expressions
a) Evaluate x – (y + 3) if x = 5 and y = -6.
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x – (y + 3) |
= |
5 – ((-6) + 3) |
Replace x with 5, and y with -6. |
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= |
5 – (-3) |
Add -6 and 3. |
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= |
5 – 9 |
Find (-3) |
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= |
-4 |
Subtract 9 from 5. |
b) Evaluate a3 + b(c – 1)2 – c2 if a = –2, b = 2.5, and c = 3.
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a3 + b(c – 1)2 – c2 |
= |
(–2)3 + 2.5(3 – 1)2 – 32 |
Replace a with –2, b with 2.5, and c with 3. |
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|
= |
–8 + 2.5(3 – 1)2 – 32 |
Find (–2)3. |
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= |
–8 + 2.5(2)2 – 32 |
Subtract 1 from 3. |
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= |
–8 + 2.5(4) – 9 |
Find 22 and 32. |
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= |
–8 + 10 – 9 |
Multiply 2.5 and 4. |
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= |
–7 |
Do all additions and subtractions from left to right. |
c) Evaluate if a = 5, n = –2, and p = –1.
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= |
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a = 5, n = –2, and p = –1 |
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= |
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Evaluate the numerator and the denominator separately. |
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= |
|
Multiply 5 and –5 in the numerator. |
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= |
or 5 |
Simplify the numerator and the denominator. Then divide. |
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