The difference of two natural numbers is 3 and the differences of their reciprocals is 3/28.find the numbers?
Answers
Answer:
Step-by-step explanation:
- The difference of two natural numbers is 3
- the differences of their reciprocals is
- The numbers
Let the greater number be x.
Let the smaller number be y.
- The difference of two natural numbers is 3
Representing the condition mathematically.
=> x - y = 3
=> x = y + 3 -----> 1
- the differences of their reciprocals is
Reciprocal of greater number =
Reciprocal of smaller number =
Representing second condition mathematically.
=> - =
Cross multiplying and multiplying on LHS,
=> =
Cross multiplying,
=> 28 ( y - x) = 3 ( xy )
Substitute the value of x from equation 1,
=> 28 ( y - y + 3) = 3 ( y + 3 ) ( y )
=> 28y - 28y + 84 = 3 ( y² + 3y )
=> 84 = 3y² + 9y
=> 3y² + 9y = 84
Converting the equation to a quadratic equation,
=> 3y² + 9y - 84 = 0 ---->2
Solving the equation further using factorization method,
Divide equation 2 by 3,
=> y² + 3y - 28 = 0
=> y² + 7y - 4y - 28 = 0
=> y ( y + 7 ) - 4 ( y + 7) = 0
=> (y + 7) ( y - 4) = 0
=> y + 7 = 0 OR y - 4 = 0
=> y - 7 OR y = 4
y = - 7 is not acceptable since - 7 is not a natural number.
•°• y = 4
Substitute y = 4 in equation 1,
=> x = y + 3
=> x = 4 + 3
=> x = 7