What is the equivalent expression of 4(2× + 10y)

If cos(2x) = tan^2(y), show that cos(2y) = tan^2(x).

At the county fair, the baxter family bought 6 hot dogs and 4 juice drinks for $12.90. the farley family bought 3 hot dogs and 4 juice drinks for $8.55. find the price of a hot dog and the price of a juice drink.

Out of 50 students surveyed, 16 have a dog. based on these results, predict how many of the 280 students in the school have a dog.