Yes you have a good example.
x = number of cookies
2*x = total amount spent on cookies at $2 each
2x-3 = amount you pay after the $3 discount is applied one time for the entire order
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a more numeric example may be this
Lets say you bought 12 cookies, so x = 12
This means it costs 2*x = 2*12 = 24 dollars total if the discount doesnt apply
However, the 3 dollar discount is there, so the grand total is 24-3 = 21 dollars.
Cherry sales as a % of total sales = (0.5 x 1.2)/(0.5 x 1.2 + 0.2 x 1.4 + 0.3 x 1.6) = 0.6 / (0.6 + 0.28 + 0.48) = 0.6 / 1.36 = 0.4412 = 44.12%
Therefore, 44.12% of the total sales will be cherry.
These two angles are alternate interior, meaning that they are the same.
Therefore, 11x-10 = 2x+17
Solve to get x = 3; the two angles both equal to 23 degrees
and since EGF and DGE together form 90, DGE = 90-23 = 67
