The sum of two natural numbers is 9 and sum of their re iprocals is 9/20 find the numbers
Answers
Answered by
71
THE TWO NUMBERS ARE 4 AND 5
SOLUTION:-
Let the numbers be x and y
GIVEN:-
- Sum of the two natural numbers is 9
x + y = 9 …(1)
- Sum of their reciprocals is 9/20
1/x + 1/y = 9/20
(x + y)/xy = 9/20 … (2)
- Using (1) in (2):-
9/xy = 9/20
xy = 20 …(3)
- Using (1) in (3)
x(9 - x) = 20
x^2 -9x + 20 = 0
(x - 5)(x - 4) = 0
x = 5 or x = 4 …(4)
- Using (4) and (1),
____________________________
If x = 5, then y = 4
___________________________
If x = 4, then y = 5
The two natural numbers are 4 and 5.
Answered by
0
Answer:
4,5
Step-by-step explanation:
Let x and y be two natural numbers.
x + y = 9 --(1)
1/x + 1/y = 9/20
y + x/xy = 9/20
9/xy = 9/20
xy = 20
x = 20/y
Substituting in equation (1)
20/y + y = 9
20 + y²/y = 9
20 + y² - 9y = 0
(y - 5) & (y - 4) are roots of the equation.
y can be 5 or 4
x can be 4 or 5
Hope it helps.....
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