To find an equivalent expression for \( (3r \cdot 5) \cdot (-3 \cdot 8) \), we can first calculate the values step by step.
Let's start by simplifying the expression:
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Calculate \( 3r \cdot 5 \): \[ 3r \cdot 5 = 15r \]
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Calculate \( -3 \cdot 8 \): \[ -3 \cdot 8 = -24 \]
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Now combine these results: \[ (3r \cdot 5) \cdot (-3 \cdot 8) = (15r) \cdot (-24) = -360r \]
Now let's look at the options provided:
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\( 15r \cdot (5 \cdot 8) \): \( 5 \cdot 8 = 40 \), so this is \( 15r \cdot 40 = 600r \), which is not equal to \(-360r\).
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\( (5 \cdot -3) \cdot -9r \): \( 5 \cdot -3 = -15 \), so this becomes \( -15 \cdot -9r = 135r \), which is not equal to \(-360r\).
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\( 24r \cdot (5 \cdot -3) \): \( 5 \cdot -3 = -15 \), so this gives \( 24r \cdot -15 = -360r \), which is equal to our original calculation.
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\( -45r \cdot 5 \): This evaluates to \( -225r \), which is also not equal to \(-360r\).
The correct equivalent expression is: \[ \boxed{24r \cdot (5 \cdot -3)} \]