Q15 of 52 Page 1

If the sum of two natural numbers is 8 and their product is 15, find the numbers.

Let the numbers be y and (8 – y);


Now,


According to the problem


y (8 – y) = 15


8y – y2 = 15


⇒ 0 = y2 – 8y + 15


y2 – 5y – 3y + 15 = 0


y (y – 5) – 3 (y – 5) = 0


(y – 3)(y – 5) = 0


y – 3 = 0 or y – 5 = 0


y = 3 or y = 5


When x = 3, numbers are 3 and 5


When x = 5, numbers are 5 and 3


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