Monica brought some postage stamps. she uses 10 stamps on letters and 5 stamps on postcards. then her grandmother gives her 20 more stamps. she now has 35 stamps left. how many stamps did monica originally have?

to find out how many stamps monica originally had, you’d have to do the equation given, “reversed”

equation given: 35 + 20 - 5 - 10

but because we are trying to find how many she originally had left, you’d have to do opposite operations (reverse) in the equation given.

35 - 20 + 5 + 10 = 30

so, this means that monica had 30 stamps originally

dude   i don't even know. i've been trying for hours.

step-by-step explanation:

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step-by-step explanation: