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The value of the expression ((x ^(2) -...

The value of the expression
`((x ^(2) - y ^(2)) ^(3) + ( y ^(2) - z ^(2)) ^(3) + (z ^(2) - x ^(2)) ^(3))/((x - y) ^(3) + ( y - z) ^(3) + (z - x ) ^(3))` is

A

`(x ^(2) - y ^(2)) (y ^(2) - z ^(2)) ( z ^(2) - x ^(2))`

B

`3 (x - x ) ( y -z) (z -x)`

C

`(x + y) (y + z) (z + x)`

D

`(3 (x + y) (y + z) (z + x)`

Text Solution

AI Generated Solution

The correct Answer is:
To find the value of the expression \[ \frac{(x^2 - y^2)^3 + (y^2 - z^2)^3 + (z^2 - x^2)^3}{(x - y)^3 + (y - z)^3 + (z - x)^3}, \] we can use the identity for the sum of cubes. ### Step 1: Identify the terms Let: - \( a = x^2 - y^2 \) - \( b = y^2 - z^2 \) - \( c = z^2 - x^2 \) ### Step 2: Check if \( a + b + c = 0 \) Now, we calculate \( a + b + c \): \[ a + b + c = (x^2 - y^2) + (y^2 - z^2) + (z^2 - x^2) = x^2 - y^2 + y^2 - z^2 + z^2 - x^2 = 0. \] Since \( a + b + c = 0 \), we can use the identity for the sum of cubes: \[ a^3 + b^3 + c^3 = 3abc. \] ### Step 3: Apply the identity to the numerator Thus, we have: \[ (x^2 - y^2)^3 + (y^2 - z^2)^3 + (z^2 - x^2)^3 = 3(x^2 - y^2)(y^2 - z^2)(z^2 - x^2). \] ### Step 4: Apply the identity to the denominator Now, let’s consider the denominator: Let: - \( p = x - y \) - \( q = y - z \) - \( r = z - x \) Again, we check if \( p + q + r = 0 \): \[ p + q + r = (x - y) + (y - z) + (z - x) = 0. \] Using the same identity for the sum of cubes: \[ (x - y)^3 + (y - z)^3 + (z - x)^3 = 3(x - y)(y - z)(z - x). \] ### Step 5: Substitute back into the expression Now substituting back into our original expression, we get: \[ \frac{3(x^2 - y^2)(y^2 - z^2)(z^2 - x^2)}{3(x - y)(y - z)(z - x)}. \] ### Step 6: Simplify the expression The \( 3 \) cancels out: \[ \frac{(x^2 - y^2)(y^2 - z^2)(z^2 - x^2)}{(x - y)(y - z)(z - x)}. \] ### Step 7: Factor the numerator Notice that \( x^2 - y^2 = (x - y)(x + y) \), \( y^2 - z^2 = (y - z)(y + z) \), and \( z^2 - x^2 = (z - x)(z + x) \). Thus, we can rewrite the numerator: \[ (x - y)(x + y)(y - z)(y + z)(z - x)(z + x). \] ### Step 8: Cancel common factors Now, substituting this back into our expression, we have: \[ \frac{(x - y)(x + y)(y - z)(y + z)(z - x)(z + x)}{(x - y)(y - z)(z - x)}. \] The common factors \( (x - y) \), \( (y - z) \), and \( (z - x) \) cancel out: \[ (x + y)(y + z)(z + x). \] ### Final Answer Thus, the value of the expression is: \[ (x + y)(y + z)(z + x). \]
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