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:
x=−593/20
Step-by-step explanation:
Answer:
8
Step-by-step explanation:
Answer:
SA = 2400 cm²
Step-by-step explanation:
SA of a cube = S² x 6 (the number of its faces)
SA = 20² x 6
SA = 400 x 6
SA = 2400 cm²