COMBINED VARIATION 1. P varies directly as S and inversely as T. 2. A varies jointly as x and y and inversely as the square of w. 3. Variable B varies directly as g and inversely as the square ofi. 4. Variable R varies directly as the square of k and inversely as the square root of u. 5.M is directly proportional to o and inversely proportional to the product of p and r.