Math, asked by sahil3716, 1 year ago

If the sum of two no. is 8 and sum of their reciprocals is 8/15 then find the numbers no. .

Answers

Answered by proudgarhwali
7

Answer:

the numbers are 5 and 3

Step-by-step explanation:

1) fund out the options ( in this case - 7+1 or 6+2 or 5+3 )

2) lcm of 5 and 3 is 15 .

3) check ur assumption

4) u will get the numbers .

hope it helps !

❤️

~ananya

Answered by ihrishi
5

Step-by-step explanation:

Let the two numbers be x and y

Therefore

x + y = 8..... (1)

&

 \frac{1}{x}  +  \frac{1}{y}  =  \frac{8}{15}  \\  \implies \frac{y + x}{xy}  = \frac{8}{15}  \\ \implies \frac{x + y}{xy}  = \frac{8}{15}...(2) \\ from \: equations \: (1) \: and \: (2) \\ \frac{8}{xy}  = \frac{8}{15} \\ \implies \:  \frac{1}{xy}  = \frac{1}{15} \\ \implies \:xy = 15 \\ now \\ (x - y)^{2}  =  (x  +  y)^{2}  - 4xy \\  = (8)^{2}  - 4 \times 15 \\  = 64 - 60 \\ \implies (x - y)^{2}  = 4 \\ x - y = 2.....(3) \\ adding \: equations \: (1) \: and \: (3) \\ x + y = 8 \\ x - y = 2  \\  -  -  -  -  -  \\ 2x = 10 \\  \implies \implies \: x =  \frac{10}{2}  \\ \implies \huge\fbox{x = 5} \\ \implies 5 + y = 8 \\ \implies \: y = 8 - 5 \\   \implies \huge\fbox {\: y = 3}

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