Q. Evaluate the expression shown below and write your answer as a fraction in simplest form.−76+(−212)Answer:
Identify common denominator: Identify the common denominator for the fractions.The fractions 76 and 212 have different denominators. To add or subtract fractions, we need a common denominator. The least common denominator (LCD) for 7 and 21 is 21.
Convert first fraction: Convert the first fraction to have the common denominator.The first fraction 76 needs to be converted to have the denominator of 21. To do this, we multiply both the numerator and the denominator by 3, because 21 is 3 times 7.76×33=2118
Rewrite with converted fraction: Rewrite the expression with the converted first fraction.Now that we have a common denominator, we can rewrite the expression as:−2118+(−212)
Add fractions: Add the fractions.Since both fractions now have the same denominator, we can add the numerators together, keeping the denominator the same.−2118+(−212)=−2118+2
Simplify numerator: Simplify the numerator.Add the numerators together.−2118+2=−2120
Check for simplification: Check for any possible simplification.The fraction −2120 is already in its simplest form because 20 and 21 have no common factors other than 1.
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