Mathorio
Answer key
Multiplying Rational Expressions
Show your work for each problem.
- 1.What is ?
- a)
- b)
- c)
- d)
Answer:
- 2.Simplify: . Enter your answer as a simplified fraction.
Answer: 1
(where )
- 3.Which value of would make undefined?
- a)
- b)
- c)
- d)
Answer:
When , the denominator , which makes the expression undefined.
- 4.Simplify: . Enter as a simplified fraction (e.g., 2/3).
Answer: 4/3
(where )
- 5.Simplify:
Answer: (x+3)/(x+5)
- Write the product as a single fraction. What is the numerator? (x+3)(x-2)
- What is the denominator? (x-2)(x+5)
- What common factor appears in both numerator and denominator? x-2
- After canceling, what is the simplified expression? (x+3)/(x+5)
- 6.What is in simplified form?
- a)
- b)
- c)
- d)
Answer:
- 7.Simplify: . Enter as a simplified fraction.
Answer: 1/(3x)
where
- 8.Simplify:
Answer: x(x-2)
- Factor (difference of squares) (x+2)(x-2)
- Factor (common factor) x(x+5)
- After factoring, which factors cancel? (x+2) and (x+5)
- What is the final simplified expression? x(x-2)
- 9.What are the restrictions on for ?
- a)
- b)
- c)
- d)
Answer:
The denominators are and . Setting each to zero: and . So .
- 10.Simplify: . Enter your answer.
Answer: x-1
where
- 11.Simplify:
Answer: x
- Factor (trinomial) (x-3)(x+2)
- Factor (difference of squares) (x+3)(x-3)
- Factor (common factor) x(x+3)
- Which three factors cancel? (x-3), (x+3), (x+2)
- What is the final answer? x
- 12.Simplify:
- a)
- b)
- c)
- d)
Answer:
- 13.Simplify: . Enter your answer as a simplified expression.
Answer: 1
where
- 14.Simplify:
Answer: 2(x+2)/(x+1)
- Factor completely (factor out 2 first) 2(x+2)(x-2)
- Factor (x+1)(x+3)
- Which factors cancel? (x-2) and (x+3)
- What is the final simplified expression? 2(x+2)/(x+1)
- 15.What are ALL the restrictions for ?
- a)
- b)
- c)
- d)
Answer:
Denominators are and . Setting each factor to zero: . Note: comes from the numerator and doesn't create a restriction.
- 16.Simplify:
Answer: x/2
- Multiply the numerators: ? 5x^2
- Multiply the denominators: ? 10x
- Simplify by canceling and x/2