Evaluate Cubes
Let's practice with numbers.
Example 1: 43 = 4 •4 •4 = 64
Let's practice evaluating with variables.
Example 2: find x3 if x = 5.
Substitute (5) in for x.
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Therefore
Let's look at a common mistake.
Remember that x3 = x •x •x so what does - x3 represent? It means (-1) •x •x •x
Example 3: find - x3 when x = 1
Substitute (1) in for x.
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Therefore
Challenge: find 3 x2 y3 when x = 4 and y = 3
Substitute (4) for x and (3) for y
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Let's sum this up. Remember that to be "cubed" means to multiply a number times itself three times.
Related Links: Math algebra Evaluate Exponents |
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