Step-by-step explanation:
5z, 5x and 5y are all unlike terms.
If there was something like <em><u>5z</u></em> + 5x <em><u>-</u></em><em><u> </u></em><em><u>3z</u></em> + 5y, then both 5z and -3z have something in common and so therefore are said to be like terms.
Hope my description helps.
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The awnser is 9.48683298051, hope I helped!
P = 2a + 3b + 4c
4c = P - 2a - 3b
c = (P - 2a - 3b)/4