The recyclables have been sorted into plastic and glass. The number of plastic items is 30 less than nine times the number of glass items. The recyclables are 85% plastic. How many glass items are there?
PLEASE HELP ASAP

Let g represent the number of glass items. Then the number of plastic items is (9g -30). If 85% of items are plastic, then 100%-85% = 15% of items are glass. The ratio of plastic to glass is ...

85%/15% = (9g -30)/g

17/3 = 9 -30/g . . . . simplify

30/g = 9 -17/3 = 10/3 . . . . . . add 30/g -17/3

g = 30(3/10) = 9 . . . . . . . . . . multiply by 3g/10

There are 9 glass items.

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Additional comment

The number of plastic items is 9(9) -30 = 51, and the total number of items is 51+9 = 60. The percentage of plastic items is 51/60 = 85%.

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There are many other ways the equation(s) could be written, including using a system of two equations. For example ...

p = 9g -30
p/(p+g) = 0.85 . . . . . plastic is 85% of the total

The recyclables have been sorted into plastic and glass. The number of plastic items is 30 less than nine times the number of glass items. The recyclables are 85% plastic. How many glass items are there? PLEASE HELP ASAP

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The recyclables have been sorted into plastic and glass. The number of plastic items is 30 less than nine times the number of glass items. The recyclables are 85% plastic. How many glass items are there?
PLEASE HELP ASAP