Find the value of cos C rounded to the nearest hundredth, if necessary

Use the elimination method to find the solution to the system of equations. 2x - 3y = -9 -x + 3y = 6

If 1/√5+1/√5+1=p+q√r , find the values of p, q and r

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?