EDGE Math 8

Perform the indicated operations and simplify the resulting expression. Then choose the correct answer.

1.	$\frac{4 x^{5}}{x^{2} - 1} \cdot \frac{x^{2} - 2 x + 1}{8 x^{2} (2 x - 1)}$

\frac{1}{2 (2 x - 1)}

\frac{x^{3}}{2 (x + 1)}

\frac{x^{3} (x - 1)}{2 (x + 1) (2 x - 1)}

none of the choices

Answer: $\frac{x^{3} (x - 1)}{2 (x + 1) (2 x - 1)}$

2.	$\frac{3 x^{2} + x - 4}{2 x + 6} \div \frac{3 x + 12}{x {}^{2}+ 2 x - 3}$

\frac{(3 x + 4) {(x - 1)}^{2}}{6 (x + 4)}

\frac{{(x - 1)}^{2}}{2}

\frac{(x + 1) (x - 1)}{2}

none of the choices

Answer: $\frac{(3 x + 4) {(x - 1)}^{2}}{6 (x + 4)}$

3.	$\frac{2}{12 x {}^{2}} + \frac{3}{9 x} - \frac{5}{4 x {}^{3}}$

\frac{x^{2} + 4 x - 15}{12 x^{3}}

\frac{4 x^{2} + x - 15}{12 x^{3}}

\frac{2 x^{2} + 3 x - 5}{12 x^{3}}

none of the choices

Answer: $\frac{4 x^{2} + x - 15}{12 x^{3}}$

4.	$\frac{3 x + 21}{x^{2} - 49} + \frac{1}{7 - x}$

\frac{2}{x - 7}

\frac{2}{x + 7}

\frac{2}{7 - x}

none of the choices

Answer: $\frac{2}{x - 7}$

5.	$\frac{3}{x^{2} + 4 x - 5} - \frac{4}{x^{2} + 6 x + 5}$

\frac{x + 7}{(x + 5) {(x - 1)}^{2}}

\frac{x + 7}{(x + 5) (x - 1) (x + 1)}

\frac{- x + 7}{(x + 5) (x - 1) (x + 1)}

none of the choices

Answer: $\frac{- x + 7}{(x + 5) (x - 1) (x + 1)}$

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