How to Solve Rational Equations? (+FREE Worksheet!)

How to Solve Rational Equations? (+FREE Worksheet!)
Tutor-style math help

Solve Rational Equations: what to notice and how to work it

Rational skill
Rational expressions are algebraic fractions. Restrictions matter from the beginning because a denominator can never be zero.

What to notice first

Factor before simplifying. You may cancel common factors, but you may not cancel pieces of sums.

Common student mistake

Do not cancel terms across plus or minus signs. In \((x+2)/x\), the x in the denominator is not a common factor of the entire numerator.

Key formulas and cues

\(\frac{a}{b}\cdot\frac{c}{d}=\frac{ac}{bd}\)
\(\frac{a}{b}+\frac{c}{d}=\frac{ad+bc}{bd}\)
\(\text{denominator}\ne0\)
\(\text{vertical asymptote: denominator}=0\text{ after simplification checks}\)

A reliable path

  1. State restrictionsFind values that make original denominators zero.
  2. Factor and simplifyCancel only factors shared by the whole numerator and denominator.
  3. Check the resultKeep original restrictions and watch for asymptotes or holes when graphing.

Worked examples

Simplify safely

Example: \(\frac{6x}{9x}\), \(x\ne0\)
  1. Cancel the common factor x.
  2. Reduce 6/9.
  3. Keep the restriction x not equal to 0.
Answer: \(\frac{2}{3},\ x\ne0\)

Find a restriction

Example: \(\frac{x+1}{x-4}\)
  1. Look at the denominator.
  2. Set x – 4 = 0.
  3. Exclude that value.
Answer: \(x\ne4\)
Try one before moving on
Try: Simplify \(\frac{x^2+3x}{x}\), \(x\ne0\).
Answer: \(x+3,\ x\ne0\).
Next step: do the matching worksheet or quiz while the method is still fresh, then come back and explain the first step in your own words.

Rational Equations – Example 2:

Rational Equations – Example 3:

Rational Equations – Example 4:

Exercises for Rational Equations

Solve Rational Equations.

  1. \(\color{blue}{\frac{10}{x+4}=\frac{15}{4x+4}}\)
  2. \(\color{blue}{\frac{x+4}{x+1}=\frac{x-6}{x-1}}\)
  3. \(\color{blue}{\frac{2x}{x+3}=\frac{x-6}{x+4}}\)
  4. \(\color{blue}{\frac{1}{x+5}-1=\frac{1}{1+x}}\)
  5. \(\color{blue}{\frac{1}{5x^2}-\frac{1}{x}=\frac{2}{x}}\)
  6. \(\color{blue}{\frac{2x}{2x-2}-\frac{2}{x}=\frac{1}{x-1}}\)
Answers
  1. \(\color{blue}{x=\frac{4}{5}}\)
  2. \(\color{blue}{x=-\frac{1}{4}}\)
  3. \(\color{blue}{x=-9}\) or \(\color{blue}{x=-2}\)
  4. \(\color{blue}{x=-3}\)
  5. \(\color{blue}{x=\frac{1}{15}}\)
  6. \(\color{blue}{x=2}\)
Original price was: $29.99.Current price is: $19.99.
Original price was: $109.99.Current price is: $54.99.

Related to This Article

What people say about "How to Solve Rational Equations? (+FREE Worksheet!) - Effortless Math"?

No one replied yet.

Leave a Reply

X
36% OFF

Limited time only!

Save Over 36%

Take It Now!

SAVE $10

It was $27.99 now it is $17.99

STAAR Algebra I for Beginners: The Ultimate Step by Step Guide to Acing STAAR Algebra I