How many gallons of 12% salt solution should a biologist add to 5 gallons of 15% salt solution to get a 14% salt solution

You are cycling around europe with friends. a cycling festival is starting soon in barcelona. it will take 4.5 hours to cycle there. how many minutes in total is this?

X2 + y 2 = 36 x + y = 6 solve the system of equations.

Sketch the region enclosed by the given curves. decide whether to integrate with respect to x or y. draw a typical approximating rectangle and label its height and width. y= 5x, y=7x^2then find the area s of the region.