You have to find the cos of angle A, so use the Pythagorean equation and trig laws to find the other side of the triangle created by angle A. 3^2 + x^2 = 5^2. x=4. This means cos(A) = 4/5). Make both cos (A) and cos (B) have equal denominators, and add. 148/185 + 60/185 = 208/185. This answer is correct, though it doesn’t appear to be any of the answers you wrote, so either those answers are wrong or you wrote something incorrectly in the problem.
Let's find out how much is the 30% discount to 47.50 dollars. => 30% = 30% /100 = .30 Now, multiply this decimal to the given amount in dollars. => 47.50 dollars * .30 = 14.25 dollars Thus the 30% discount of 47.50 dollars is 14.25 dollars.