Math, asked by ugzhahahah, 1 month ago

The sum of two numbers is 13 and the sum of their reciprocal is 13/42. Find the numbers​

Answers

Answered by midhunmadhu1987
1

Step-by-step explanation:

see the attached document

Attachments:
Answered by Anonymous
13

Answer:

6 and 7

Step-by-step explanation:

Given:-

The sum of two numbers is 13 and the sum of their reciprocal is 13/42.

To Find:-

The numbers

Solution:-

Let first number be x

Other number = 13-x

Reciprocal of 1st number = 1/x

Reciprocal of 2nd number = 1/(13-x)

The sum of their reciprocals is 13/42. So,

ACQ

 \therefore \:  \rm \:  \frac{1}{x}  +  \frac{1}{13 - x}  =  \frac{13}{42}  \\   \rm \: LCM \: of \:( x )\: and \: (13 - x) =x(13 - x) \\  \rightharpoonup \rm \:  \frac{ \cancel{(x)}(13 - x)} {\cancel{x} }+  \frac{(x) \cancel{(13 - x)}} { \cancel{13 - x}}  =  \frac{13}{42} (x)(13 - x) \\ \rightharpoonup \rm \: 13 - x + x =  \frac{13}{42} (13x -  {x}^{2} ) \\  \rm \: By \: cross - multiplying \: we \: get, \\ \rightharpoonup \rm \:42(13) = 13(13x -  {x}^{2} ) \\ \rightharpoonup \rm \:546 = 169x - 13 {x}^{2}  \\ \rightharpoonup \rm \:13 {x}^{2}   - 169x - 546 = 0 \\  \rm \:   Dividing \: 13 \: to \: all \\ \rightharpoonup \rm \: {x}^{2}  - 13x  +  42 = 0 \\ \rightharpoonup \rm \: {x}^{2} - 6x - 7x + 42 = 0 \\  \rightharpoonup \rm \:x(x - 6) - 7(x - 6) = 0 \\ \rightharpoonup \rm \:(x - 6)(x - 7) = 0

If x-6=0

x=6

If x-7=0

x=7

So two number are 6 and 7

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