Polynomials and Rational Expressions

9000079206

Level: 
A
Assuming \(x\neq 0\), \(y\neq 0\), \(x\neq y\), simplify the following expression. \[ { \frac{1} {x^{2}} - \frac{1} {y^{2}} \over -\frac{1} {y} + \frac{1} {x}} \]
\(\frac{x+y} {xy} \)
\(-\frac{x+y} {xy} \)
\(\frac{1} {y} -\frac{1} {x}\)
\(\frac{1} {x} -\frac{1} {y}\)

9000079208

Level: 
B
Assuming \(x\neq 0\) and \(y\neq 0\), simplify the following expression. \[ \left (\frac{x^{-2}y^{2}} {x^{0}y^{-8}}\right )^{-2} : \frac{x^{2}} {x^{-4}y^{7}} \]
\(\frac{1} {x^{2}y^{13}} \)
\(\frac{y^{13}} {x^{2}} \)
\(\frac{y^{15}} {x^{6}} \)
\(\frac{x^{4}} {y^{27}} \)