Substitution
We can be given the number for the letter p = 4. This means we can replace p by 4 in an expression.
| Therefore |
p + 2 |
= 4 + 2 = 6 |
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p – 1 |
= 4 – 1 = 3 |
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3p |
= 3 x 4 = 12 |
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p |
= 4 = 2 |
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2
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2 |
p3 = 4 x 4 x 4 = 64
We say that we have substituted 4 for p in the expression.
Example: Given t = 3 and m = 5, find the value of the following:
7t = 7 x 3 = 21
| 2t + 4m |
= 2 x 3 + 4 x 5 |
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= 6 + 20 |
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= 26 |
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| 5t2 = 5 x 3 squared |
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= 5 x 9 |
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= 45 |
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| 4m + 2t |
= 4 x 5 + 2 x 3 |
| 10 |
10 |
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= 8 |
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