PSAT Math : How to subtract rational expressions with different denominators

Study concepts, example questions & explanations for PSAT Math

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Example Questions

Example Question #1 : Rational Expressions

Simplify.

Possible Answers:

Correct answer:

Explanation:

Determine an LCD (Least Common Denominator) between  and .

LCD = 

Multiply the top and bottom of the first rational expression by , so that the denominator will be .

Distribute the  to .

Now you can subtract because both rational expressions have the same denominators.

Final Answer. 

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