Adding and Subtracting Rational Numbers

Which situation could be represented by the equation: - 30 + 30 = 0 ?

• Jacob bought a hat for $30. He then bought some headphones for $30.

• Charmeal loaned $30 to her brother. She then paid her back $30 the next day.

• Shoney drove 30 miles to the library. She then drove 30 more miles to her college.

• Alysha filled a tank with 30 gallons of water. She then filled the tank with 30 more gallons.

Mr. Smith has an account balance of -$275.78.  He deposits $539.20 into his account.  What is Mr. Smith's account balance now?

• $813.98

• $263.42

• $539.78

• $345.98

What is the value of (-115) + 23?

• -138

• 92

• 138

• -92

5/8 + 1/4

• 6/12

• 7/8

• 6/8

• -7/8

⅞ - (-⅝)

• 2/8

• -2/8

• -1 4/8

• 1 4/8

5.8 -1.9

• 7.7

• -7.7

• 3.9

• -3.9

-11.6 - 2.9

• -14.5

• 15.5

• -8.7

• 8.7

When adding and subtracting rational expressions, my first step should be to:

• Combine like terms in the numerators.

• Determine a Least Common Denominator.

• Factor all of the numerators and all of the denominators.

• Change the operator to multiplication and reciprocate the second fraction.

Find the LCD of the following rational numbers

5/4 and 2/3

• 12

• 5

• 24

• 7

Find the LCD of the following rational numbers

• 10

• 5

• 15

• 20