It is 30 feet BELOW the platform, so the number is -20 because the platform is 10 feet above ground level.
Her elevation is - 20 because she is 10 feet above ground level, which is 10, and she digs 30 feet down so 10 - 30 is -20.
Hope this helps. :)
Answer:
757.08 should be your answer :D
Step-by-step explanation:
Have a good day :)
Answer:
13a
Step-by-step explanation:
9a + 3a + a = 13a