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Two equations (I) and (II) are given in ...

Two equations (I) and (II) are given in each question. On the basis of these equations you have to decide the relation between 'x' and 'y' and given answer
I. `( x)/( x + 7) + ( x + 7)/( x) = 12 `
II ` ( y)/( y + 8) + ( y + 8)/( y) = 16 `

A

If ` x gt y `

B

If ` x le y `

C

If ` x lt y `

D

If x = y or Relation cannot be established

Text Solution

AI Generated Solution

The correct Answer is:
To solve the given equations and determine the relationship between \( x \) and \( y \), we will follow these steps: ### Step 1: Solve Equation I The first equation is given as: \[ \frac{x}{x + 7} + \frac{x + 7}{x} = 12 \] To simplify, we will find a common denominator: \[ \frac{x^2 + (x + 7)^2}{x(x + 7)} = 12 \] Expanding \( (x + 7)^2 \): \[ \frac{x^2 + (x^2 + 14x + 49)}{x(x + 7)} = 12 \] This simplifies to: \[ \frac{2x^2 + 14x + 49}{x(x + 7)} = 12 \] Cross-multiplying gives: \[ 2x^2 + 14x + 49 = 12x^2 + 84x \] Rearranging the equation: \[ 0 = 10x^2 + 70x - 49 \] Thus, we have: \[ 10x^2 + 70x - 49 = 0 \] ### Step 2: Apply the Quadratic Formula for Equation I Using the quadratic formula \( x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \): Here, \( a = 10 \), \( b = 70 \), and \( c = -49 \). Calculating the discriminant: \[ b^2 - 4ac = 70^2 - 4 \cdot 10 \cdot (-49) = 4900 + 1960 = 6860 \] Now substituting into the formula: \[ x = \frac{-70 \pm \sqrt{6860}}{20} \] Calculating the square root: \[ \sqrt{6860} \approx 82.8 \] Thus: \[ x = \frac{-70 \pm 82.8}{20} \] Calculating the two possible values for \( x \): 1. \( x_1 = \frac{12.8}{20} = 0.64 \) 2. \( x_2 = \frac{-152.8}{20} = -7.64 \) ### Step 3: Solve Equation II The second equation is: \[ \frac{y}{y + 8} + \frac{y + 8}{y} = 16 \] Finding a common denominator: \[ \frac{y^2 + (y + 8)^2}{y(y + 8)} = 16 \] Expanding \( (y + 8)^2 \): \[ \frac{y^2 + (y^2 + 16y + 64)}{y(y + 8)} = 16 \] This simplifies to: \[ \frac{2y^2 + 16y + 64}{y(y + 8)} = 16 \] Cross-multiplying gives: \[ 2y^2 + 16y + 64 = 16y^2 + 128y \] Rearranging: \[ 0 = 14y^2 + 112y - 64 \] Thus, we have: \[ 14y^2 + 112y - 64 = 0 \] ### Step 4: Apply the Quadratic Formula for Equation II Using the quadratic formula \( y = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \): Here, \( a = 14 \), \( b = 112 \), and \( c = -64 \). Calculating the discriminant: \[ b^2 - 4ac = 112^2 - 4 \cdot 14 \cdot (-64) = 12544 + 3584 = 16128 \] Now substituting into the formula: \[ y = \frac{-112 \pm \sqrt{16128}}{28} \] Calculating the square root: \[ \sqrt{16128} \approx 126.9 \] Thus: \[ y = \frac{-112 \pm 126.9}{28} \] Calculating the two possible values for \( y \): 1. \( y_1 = \frac{14.9}{28} \approx 0.53 \) 2. \( y_2 = \frac{-238.9}{28} \approx -8.53 \) ### Step 5: Compare Values of \( x \) and \( y \) From the results: - \( x \) can be \( 0.64 \) or \( -7.64 \) - \( y \) can be \( 0.53 \) or \( -8.53 \) ### Conclusion 1. If we take the positive values: \( x = 0.64 \) and \( y = 0.53 \), then \( x > y \). 2. If we take the negative values: \( x = -7.64 \) and \( y = -8.53 \), then \( x < y \). Since we have both \( x > y \) and \( x < y \), we cannot establish a definitive relationship between \( x \) and \( y \).
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