4th or 5th time posting Find area of shaded region

Area of addition and subtraction, trigonometry, and sohachtoa.

What is x and y (use substitution? ) 5x+3y=38 and y=3x+8?

One-third of the people from country a claim that they are from country b, and the rest admit they are from country a. one-fourth of the people from country claim that they are from country a, and the rest admit they are from country b. in a combined census of the two countries, one-half of the total claimed to be from a. what is the ratio of the populations of country a to that of country b.

Marla bought a book for $12.95, a binder for $3.49, and a backpack for $44.99. the sales tax rate is 6%. find the amount of tax and the total she paid for these items