Answer:
Step 1
Step-by-step explanation:
Mark simplified 3/5 + 5/8 using the steps below:
Step 1: 3/5 * 8/5
Step 2: 3 * 8 / 5 * 5
Step 3: 24/5
Step 4: 4 4/5
Mark's error is in Step 1 where he changed the addition sign to multiplication sign.
The correct solution is:

Answer
r = 20.25
this is the awnser i know im only in 6th grade but im good at math
<h3>
Answer: 60</h3>
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Explanation:
Multiply the two values to get 4*15 = 60
Then divide by the GCF 1 to get 60/1 = 60. The GCF being 1 means the result hasn't changed.
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Another example would be: "Find the LCM of 6 and 8". We would first do 6*8 = 48, then divide by the GCF 2 to get 48/2 = 24. The LCM of 6 and 8 is 24.