Question

the sum of two number is 15 if sum of their resiprocal is 3÷10 find number

Answer 1

x+y=15

y+x/xy=3/10

1/x + 1/15-x=3/10

150=45x-3x2

3x2-45x-150=0

x2-15-50=0

Therefore no.are 5 and 10

7 years ago

let the numbers be x and y

so

x+y = 15 -------------------------(i)

and 1/x + 1/y = 3/10

==> (y + x)/xy = 3/10 (putting (i))

15/ xy = 3/10

5/xy = 1/10

xy = 50 --------------------(ii)

x = 50/y -----------------------(iii)

50/y + y = 15

50 + y2 = 15y

y2 - 15y + 50 = 0

(y-10)(y-5) = 0

y = 10 and y = 5

now there will be 2 numbers for 'x'

substituting y as 10 we get

x = 5 ;

substituting y as 5 we get

x = 10;

so the numbers are x = 10 and y = 5 and viceversa !

Answer 2

solution is this please follow me