Mathorio
Answer key
Simplifying Rational Expressions
Show your work for each problem.
- 1.Simplify
- a)
- b)
- c)
- d)
Answer:
, where .
- 2.Simplify and enter the coefficient only (the number in front of ).
Answer: 3
. The coefficient is 3.
- 3.Which expression is already in simplest form?
- a)
- b)
- c)
- d)
Answer:
In , the in the numerator is a term, not a factor, so it cannot be canceled. The other expressions can all be simplified further.
- 4.Simplify
Answer: 2x^2y
- What is ? 2
- What is ? x^2
- What is ? y
- Combine: what is the simplified form? 2x^2y
- 5.Simplify
- a)
- b)
- c)
- d)
Answer:
. So , where .
- 6.What is the restriction for after simplifying? (Enter the value that cannot equal)
Answer: -5
The original denominator is , which equals zero when . Even after simplifying to , we must exclude .
- 7.Simplify
Answer: x + 2
- Factor the numerator. Find two numbers that multiply to 2 and add to 3. (x + 1)(x + 2)
- Identify the common factor between numerator and denominator. x + 1
- After canceling the common factor, what is the simplified form? x + 2
- 8.Simplify
- a)
- b)
- c)
- d)
Answer:
, where and .
- 9.Simplify
Answer: (x - 2)/(x + 2)
- Factor the numerator (it's a perfect square trinomial). (x - 2)^2
- Factor the denominator (difference of squares). (x + 2)(x - 2)
- What is the common factor? x - 2
- What is the simplified form? (x - 2)/(x + 2)
- 10.Simplify . Enter your answer as a single integer or fraction.
Answer: -1
, where . When numerator and denominator are opposites, the result is .
- 11.Simplify
- a)
- b)
- c)
- d)
Answer:
, where and .
- 12.Simplify
Answer: -(x + 3)/(x - 3)
- Rewrite by factoring out to get standard form. -(x^2 - 9)
- Now factor as a difference of squares. (x + 3)(x - 3)
- Factor the denominator (perfect square). (x - 3)^2
- Combine and simplify. What is the final answer? -(x + 3)/(x - 3)
- 13.How many restrictions does have after simplifying? Enter a number.
Answer: 2
. The original denominator is zero when or . So there are 2 restrictions.
- 14.Simplify
- a)
- b)
- c)
- d)
Answer:
- 15.Simplify
Answer: (x^2 + 2x + 4)/(x + 2)
- Recognize the numerator pattern. is a... difference of cubes
- Factor using . What is ? x^2 + 2x + 4
- Factor the denominator (difference of squares). (x + 2)(x - 2)
- What is the simplified form? (x^2 + 2x + 4)/(x + 2)
- 16.Which value makes the expression undefined?
- a)
- b)
- c)
- d)
Answer:
The denominator when . Division by zero is undefined.
- 17.If simplifies to , what is the value of ?
Answer: -1
. Comparing with , we get .
- 18.Simplify
Answer: (x + 4)/(x - 2)
- Factor the numerator. What two numbers multiply to 12 and add to 7? (x + 3)(x + 4)
- Factor the denominator. What two numbers multiply to -6 and add to 1? (x + 3)(x - 2)
- What factor cancels? x + 3
- What is the simplified expression? (x + 4)/(x - 2)