1/5 + 1/4 =1/x
4x + 5x = 20
9x = 20
x = 2.22 hours Answer
1) An example of a compound machine could be a pair of Scissors. Their are two different simple machines in the Scissors which make up the compound machine. Both of them being a Lever, and a Fulcrum.
Hope this helps!
Answer:
The solidifying/cooling and crystallizing of magma causes igneous rocks to form.
