Expressing in Negative Exponents
Source:
February 1, 2009
Problem Statement
When simplified and expressed with negative exponents, the expression (x \plus{} y)^{ \minus{} 1}(x^{ \minus{} 1} \plus{} y^{ \minus{} 1}) is equal to:
(A)\ x^{ \minus{} 2} \plus{} 2x^{ \minus{} 1}y^{ \minus{} 1} \plus{} y^{ \minus{} 2} \qquad(B)\ x^{ \minus{} 2} \plus{} 2^{ \minus{} 1}x^{ \minus{} 1}y^{ \minus{} 1} \plus{} y^{ \minus{} 2} \qquad(C)\ x^{ \minus{} 1}y^{ \minus{} 1}
(D)\ x^{ \minus{} 2} \plus{} y^{ \minus{} 2} \qquad(E)\ \frac {1}{x^{ \minus{} 1}y^{ \minus{} 1}}