a natural number decreased by 30 times its reciprocal is 1. find the natural number

Sagot :

Let n be the number
      1/n  = reciprocal of the number
      
Equation:
    n - 30(1/n) = 1
    
    (n) (n) - 30 (n)  = (1)(n)
                  n
      n² - 30 = n
      n² - n - 30 = 0

Solve by factoring:
    (n - 6)  (n + 5) = 0
 
    n-6 = 0                  n+5 = 0
    n = 6                      n = -5

The problem is looking for natural number, so choose the positive solution/rrot which is n= 6

Final Answer:  The natural number is 6.

TO Check:
   n - 30(1/n) = 1
   6 - 30 (1/6) = 1
   6 - (30/6) = 1
    6 - 5 = 1
          1 = 1