The product of two positive numbers is 616. If the ratio of the difference of their cubes to the cube of their difference is 157:3, then the sum of the two numbers is
Consider two numbers denoted as x and y Given that x × y = 616 Also , \(\frac{x³ - y³}{(x - y)³} = \frac{157}{3}\) Let's assume that x³ - y³ = 157k and (x - y)³ = 3k we know that (x - y)³ = x³ - y³ - 3xy(x - y) ⇒ (3k)³ = 157k - 3×616(3k)1/3 ⇒ 154k = 3 × 616 × (3k)1/3 ⇒ k = 3 × 616 / 154 × (3k)1/3 ⇒ k = 12 × (3k)1/3 ⇒ k³ = 12³ × 3 × k ⇒ k² = 3 × 12³ ⇒ k =72
∴ x - y = (3k)1/3 = (3×72)1/3 = 6 Also , ( x + y )² = ( x - y )² + 4xy ⇒ ( x + y )² = 6² + 3 × 616 = 2500 ⇒ ( x + y ) = 50 Therefore , Sum of the two numbers is 50