Add and subtract rational expressions by finding the least common multiple

The  exercise appears under the Algebra II Math Mission. This exercise practices mastering the skill of rational expression addition and subtraction by working with expressions whose denominators aren't factored and may or may not have shared factors.

Types of Problems
There is one type of problem in this exercise:


 * 1) Add/Subtract the following rational expressions: This problem has the sum or difference of two rational expressions. The student is asked to combine the rational expressions and write the answer in the space provided. Students may keep the denominator in its factored form. Add and subtract rational expressions by finding the least common multiple.PNG

Strategies
As with most work with rational expressions, knowledge and comfort with fractions are important to ensuring success on this exercise.
 * 1) The general process to combine rational expressions is to factor the denominators, make common denominators, add or subtract as requested, factor and simply as possible.
 * 2) The numerator should be expanded and like terms collected.
 * 3) The denominator may be left in a factored form and still be accepted.
 * 4) Like terms and factors do need to be reduced from the top and bottom.

Real-life Applications

 * 1) Rational expressions and equations appear often in work rate word problems.
 * 2) Rational expressions and equations also can occur in distance=rate*time ($$d=r\times t$$) problem