If ab = 10, and a2 + b2 = 30, solve for y in the equation, y = (a + b)2.
y = (a + b)2. Expanding the equation results in y = a2 + b2 + 2ab. You know that a2 + b2 = 30, and ab = 10. When you substitute these known values into the equation, you get y = 30 + 2(10). Solving for y, results in y = 50.