These 22 problems practice simplifying, multiplying, dividing, adding, and subtracting rational expressions, rewriting them with long division, and solving rational equations (A-APR.D.6, A-APR.D.7, A-REI.A.2).
The last problems are work, rate, and cost applications. Check every solution of a rational equation in the original equation, because extraneous solutions are common.
Problem 1: Find the excluded values
Find all values of \(x\) that must be excluded.
- \(\frac{5}{x-4}\)
- \(\frac{x+1}{x^{2}-9}\)
- \(\frac{7}{x^{2}+x-6}\)
Problem 2: Simplify monomial quotients
Simplify. Assume no denominator is zero.
- \(\frac{18x^{4}}{24x^{2}}\)
- \(\frac{20x^{3}y}{35xy^{2}}\)
Problem 3: Simplify by factoring
Simplify each expression and state the excluded values.
- \(\frac{x^{2}-9}{x^{2}+x-6}\)
- \(\frac{x^{2}+5x+6}{x^{2}+3x+2}\)
Problem 4: Why the graph has a hole
The graph of \(y=\frac{x^{2}-1}{x+1}\) is shown. Simplify the expression, then explain why the graph has a hole and give its coordinates.
Problem 5: Opposite factors
Simplify. State the excluded values.
- \(\frac{4-x}{x-4}\)
- \(\frac{9-x^{2}}{x-3}\)
Problem 6: Multiply rational expressions
Multiply and simplify.
- \(\frac{x^{2}-4}{x+5}\cdot\frac{2x+10}{x-2}\)
- \(\frac{x^{2}+3x}{x^{2}-1}\cdot\frac{x-1}{x}\)
Problem 7: Divide rational expressions
Divide and simplify.
- \(\frac{x^{2}-x-6}{x+4}: \frac{x-3}{x^{2}-16}\)
- \(\frac{6x^{2}}{5y}: \frac{3x}{10y^{2}}\)
Problem 8: Same denominator
Add or subtract and simplify.
- \(\frac{3x+1}{x+4}+\frac{2x-5}{x+4}\)
- \(\frac{5x+2}{x-1}-\frac{2x-7}{x-1}\)
Problem 9: Different denominators
Add or subtract and simplify.
- \(\frac{2}{x}+\frac{3}{x+1}\)
- \(\frac{5}{6x}-\frac{1}{4x^{2}}\)
Problem 10: Binomial denominators
Subtract and simplify: \(\frac{4}{x-2}-\frac{3}{x+3}\)
Problem 11: Factor the denominators first
Combine and simplify.
- \(\frac{x}{x^{2}-9}-\frac{1}{x-3}\)
- \(\frac{2}{x^{2}-x-6}+\frac{1}{x+2}\)
Problem 12: Rewrite using long division
Use long division to rewrite each expression as a polynomial plus a remainder term.
- \(\frac{x^{2}+3x+5}{x+1}\)
- \(\frac{2x^{2}-x-7}{x-2}\)
Problem 13: Rewrite by inspection
Rewrite each expression in the form \(a+\frac{r}{\text{denominator}}\).
- \(\frac{2x+7}{x+3}\)
- \(\frac{3x-4}{x-1}\)
Problem 14: Solve a proportion-style equation
Solve each equation and check.
- \(\frac{3}{x}=\frac{5}{x+4}\)
- \(\frac{2}{x-1}=\frac{6}{x+3}\)
Problem 15: Rational equation with a quadratic
Solve \(\frac{1}{x}+\frac{1}{x+3}=\frac{1}{2}\). Check each solution.
Problem 16: Spot the extraneous solution
Solve \(\frac{x^{2}}{x-3}=\frac{9}{x-3}\) algebraically. Then use the graphs to explain which answer is extraneous.
Problem 17: Equation with no solution
Solve \(\frac{x}{x-4}=\frac{4}{x-4}+2\).
Problem 18: Average cost
The school store orders custom hoodies. The total cost of \(n\) hoodies is \(C(n)=120+8n\) dollars, so the average cost per hoodie is \(A(n)=\frac{120+8n}{n}\).
- How many hoodies make the average cost \(\$11\)?
- Rewrite \(A(n)\) as \(8+\frac{120}{n}\). What value does the average cost approach as \(n\) gets very large?
Problem 19: Painting a fence together
Maya can paint a fence in \(6\) hours. Jamal can paint the same fence in \(3\) hours. How long does it take them together?
Problem 20: Fill pipe and drain
A pipe can fill a tank in \(4\) hours. A drain can empty a full tank in \(12\) hours. Both are open at the same time with the tank empty. How long does it take to fill the tank?
Problem 21: Boat on a river
Ethan’s kayak goes \(24\) miles downstream and \(8\) miles back upstream in a total of \(5\) hours. The river current is \(2\) mph. Find the speed \(r\) of the kayak in still water.
Problem 22: Decorating the gym
Mei and Aisha can decorate the gym together in \(4\) hours. Mei can do the whole job alone in \(6\) hours. How long would Aisha take to do it alone?
See every chapter on the Algebra 2 math page.



