Here's something I learned, if that's a go math text book the answers are always in the last couple pages of the book
(18 neclaces)/(12 days) = 1.5 necklaces/day
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Rate is generally expressed in terms of quantity per time period. ("Per" means "divided by" here.) So, to find the rate, you divide the quantity by the corresponding time period, as above. There are other sorts of rates, but this is perhaps the most common.
Try 40x+20+4kxexponet2+4kx+k
I can't really help you with what is in your house......
