91Ó°ÊÓ

Perform the indicated operation or operations. $$\frac{3 x y+a y+3 x b+a b}{9 x^{2}-a^{2}} \div \frac{y^{3}+b^{3}}{6 x-2 a}$$

In Palo Alto, California, a government agency ordered computer-related companies to contribute to a pool of money to clean up underground water supplies. (The companies had stored toxic chemicals in leaking underground containers.) The formula $$ C=\frac{2 x}{100-x} $$ models the cost, \(C\), in millions of dollars, for removing \(x\) percent of the contaminants. Use this mathematical model to solve Exercises \(71-72\). What percentage of the contaminants can be removed for \(\$ 2\) million?

Perform the indicated operation or operations. Simplify the result, if possible. $$\frac{(y-3)(y+2)}{(y+1)(y-4)}-\frac{(y+2)(y+3)}{(y+1)(4-y)}-\frac{(y+5)(y-1)}{(y+1)(4-y)}$$

Solve: \(2-3(x-2)=5(x+5)-1\)

Simplify each rational expression. If the rational expression cannot be simplified, so state. $$\frac{y^{2}-y-12}{4-y}$$

Add or subtract as indicated. Simplify the result, if possible. $$\frac{x+3}{x^{2}+x-2}-\frac{2}{x^{2}-1}$$

Multiply: \(\quad(x+y)\left(x^{2}-x y+y^{2}\right)\)

Simplify each rational expression. If the rational expression cannot be simplified, so state. $$\frac{y^{2}-7 y+12}{3-y}$$

In Palo Alto, California, a government agency ordered computer-related companies to contribute to a pool of money to clean up underground water supplies. (The companies had stored toxic chemicals in leaking underground containers.) The formula $$ C=\frac{2 x}{100-x} $$ models the cost, \(C\), in millions of dollars, for removing \(x\) percent of the contaminants. Use this mathematical model to solve Exercises \(71-72\) What percentage of the contaminants can be removed for \(\$ 8\) million?

Perform the indicated operation or operations. $$\frac{5 x y-a y-5 x b+a b}{25 x^{2}-a^{2}} \div \frac{y^{3}-b^{3}}{15 x+3 a}$$