The sum of two numbers is 17 and the sum of their square is 145. Find the larger number.

Question

How do I do the steps to figure out this word proble? Can someone please help me?

Answer 1

x + y = 17      x = 17 - y

x² + y² = 145

(17-y)² + y² = 145

289 - 34y + y2 = 145

2y² - 34y + 144 = 0

y² - 17y + 72 = 0

(y - 8)(y - 9) = 0

y - 8 = 0    or   y - 9 = 0

y = 8         or   y = 9