A type of cake requires 150g of flour. Another requires 750g of flour. At most, 2.25kg of flour is available, how do you represent this in an inequality?

A dog owner wants to build a rectangular dog run usiing no more than 20m of fencing. She wants the run to have an area of at least 20 square meters. How do you represent this problem as an inequality?

lets define SmallCake as a number of cakes that require 150g of flour, and
lets define BigCake as a number of cakes that require 750g of flour
notice that SmallCake and BigCake must be natural numbers

so our inequality is:
SmallCake*150g + BigCake*750g <= 2250g

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rectangle is not a square, so lets define W as width and H as height of the dog run

then our (system of) inequalities look like this:
2*W + 2*H <= 20 (that means that the total amount of fence used is not more then 20m)
W*H >= 20 (that means that the area must be bigger than 20 square meters)

Kresho

Thank you, you've helped me out a lot, I really appreciate it.