Question 5 - of 19 step 1 of 1 \( z \) varies directly as the cube of \( x \) and inversely as \( y \). If \( z=237 \) when \( x=10 \) and \( y=2 \), find \( z \) if \( x=8 \) and \( y=3 \). Round your answer to two decimal places if necessary.

a) \( \quad x^{2}=49 \)

\( \frac{\frac{\frac{2}{x}}{\frac{2}{x^{2}}+\frac{7}{x}}}{\frac{\frac{2}{x}}{\frac{2}{x^{2}}+\frac{7}{x}}=\square \text { (Simplify your answer.) }} \)

Perform the indicated operation. \( \frac{8}{x^{2}-2 x-35}+\frac{7}{x-7} \) \( \frac{8}{x^{2}-2 x-35}+\frac{7}{x-7}=\square( \) Simplify your answer. \( ) \)

Simplify. \( \frac{\frac{3}{x+5}}{x-5}-\frac{3}{x^{2}-25} \) \( \frac{\frac{3}{x+5}}{\frac{3}{x-5}-\frac{3}{x^{2}-25}}=\square \) (Use integers or fractions for any numbers in the expression.)

Reste \( 2 x^{2}-7 x-1 \) de la suma de \( x^{2}+9 x-4 \) y \( -5 x^{2}-7 x+10 \)