the product of a number and 8 less than the number is 65 what are the numbers

Let first number = a
Second number = b = a - 8
According to question :
                                  a * (a - 8) = 65
                                  a2 - 8a  = 65
                                  a2 - 8a - 65 = 0
                                  a2 - 13a + 5a - 65 = 0
                                  a (a - 13) + 5 (a - 13) = 0
                                 ( a - 13) (a + 5) = 0
                                  a = 13          &          a = -5
Does equation is satisfied by :
(i) a = 13
     b = 13 - 8 = 5
        13 * 5 = 65
                              Yes.

So, first number is 13 & second number is 5.



...............Hope it will work
  • 2
The number =x
then,
x(x-8)=65
x2-8x=65
x2-8x+42=65+42
(x-4)2=81
x-4=root of 81
x-4=+/-9
x=9+4=13
or

x=-9+4=-5.
value of x=13,-5.
  • 2
13 an 5
  • 1
Let the number be x then the other number will be x-8 x(x-8)=65 solving this equation you will get the value of x
  • 0
13 and 5
  • 0
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