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If a, b and c are in G.P and x and y, re...

If a, b and c are in G.P and x and y, respectively , be arithmetic means between a,b and b,c then

A

`a/x+c/y=2`

B

`a/x+c/y=c/a`

C

`1/x +1/y=2/b`

D

`1/x+1/y=2/ac`

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To solve the problem, we need to verify the two expressions involving \( a, b, c \) (which are in geometric progression) and \( x, y \) (which are arithmetic means). ### Step-by-step Solution: 1. **Understanding the Given Information:** - Since \( a, b, c \) are in geometric progression (G.P.), we have: \[ b^2 = ac \] 2. **Finding the Arithmetic Means:** - The arithmetic mean \( x \) between \( a \) and \( b \) is given by: \[ x = \frac{a + b}{2} \] - The arithmetic mean \( y \) between \( b \) and \( c \) is given by: \[ y = \frac{b + c}{2} \] 3. **Finding the Expression \( \frac{a}{x} + \frac{c}{y} \):** - Substitute the values of \( x \) and \( y \): \[ \frac{a}{x} = \frac{a}{\frac{a + b}{2}} = \frac{2a}{a + b} \] \[ \frac{c}{y} = \frac{c}{\frac{b + c}{2}} = \frac{2c}{b + c} \] - Now, adding these two fractions: \[ \frac{a}{x} + \frac{c}{y} = \frac{2a}{a + b} + \frac{2c}{b + c} \] - To add these fractions, we need a common denominator: \[ = \frac{2a(b + c) + 2c(a + b)}{(a + b)(b + c)} \] - Simplifying the numerator: \[ = \frac{2ab + 2ac + 2ca + 2cb}{(a + b)(b + c)} = \frac{2(ab + ac + bc)}{(a + b)(b + c)} \] 4. **Verifying the Expression \( \frac{1}{x} + \frac{1}{y} \):** - We can find \( \frac{1}{x} \) and \( \frac{1}{y} \): \[ \frac{1}{x} = \frac{2}{a + b} \] \[ \frac{1}{y} = \frac{2}{b + c} \] - Adding these gives: \[ \frac{1}{x} + \frac{1}{y} = \frac{2}{a + b} + \frac{2}{b + c} \] - Again, finding a common denominator: \[ = \frac{2(b + c) + 2(a + b)}{(a + b)(b + c)} = \frac{2(b + c + a + b)}{(a + b)(b + c)} = \frac{2(a + 2b + c)}{(a + b)(b + c)} \] ### Final Results: - We have shown that: - \( \frac{a}{x} + \frac{c}{y} = \frac{2(ab + ac + bc)}{(a + b)(b + c)} \) - \( \frac{1}{x} + \frac{1}{y} = \frac{2(a + 2b + c)}{(a + b)(b + c)} \)

To solve the problem, we need to verify the two expressions involving \( a, b, c \) (which are in geometric progression) and \( x, y \) (which are arithmetic means). ### Step-by-step Solution: 1. **Understanding the Given Information:** - Since \( a, b, c \) are in geometric progression (G.P.), we have: \[ b^2 = ac ...
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