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The Difference of Two Numbers is 4. If the Difference of Their Reciprocals is 4/21. Find the Numbers.

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The difference of two numbers is 4. If the difference of their reciprocals is 4/21. Find the numbers.

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Let the two numbers be x and x - 4

Given that the difference of two numbers is 4.

By the given hypothesis, we have

`1/(x-4)-1/x=4/21`

`rArr(x-x+4)/(x(x-4))=4/21`

⇒ 84 = 4x(x – 4)

⇒ ЁЭСе2 - 4ЁЭСе - 21 = 0

⇒ ЁЭСе2 - 7ЁЭСе + 3ЁЭСе - 21 = 0

⇒ ЁЭСе(ЁЭСе - 7) + 3(ЁЭСе - 7) = 0

⇒ (ЁЭСе - 7)(ЁЭСе + 3) = 0

⇒ ЁЭСе = 7 ЁЭСЬЁЭСЯ ЁЭСе = -3 and

If x = -3, x – 4 = -3 - 4 = -7

Hence, required numbers are 3, 7 and -3, -7

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рдЕрдзреНрдпрд╛рдп 4: Quadratic Equations - Exercise 4.7 [рдкреГрд╖реНрда релреи]

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рдЖрд░.рдбреА. рд╢рд░реНрдорд╛ Mathematics [English] Class 10
рдЕрдзреНрдпрд╛рдп 4 Quadratic Equations
Exercise 4.7 | Q 16 | рдкреГрд╖реНрда релреи

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