What is he domain of the some and cosine functions a)all real numbers b)all whole numbers c)all positive real numbers d)all real numbers other than 0

Zoey made 5 1/2 cups of trail mix for a camping trip. she wants to divide the trail mix into 3/4 cup servings. a. ten people are going on the trip. can zoey make enough 3/4 cup servings so that each person gets one serving? b. what size would the servings need to be for everyone to have a serving?

Solve for x and y: 217x + 131y = 913; 131x + 217y = 827

Can someone tell me if this is perpendicular? !