# Question Video: Understanding Subtraction of Rational Numbers as Adding the Inverse Mathematics • 7th Grade

Find a subtraction expression that is equivalent to the addition expression −8.38 + (−2.2). [A] −8.38 − 2.2 [B] −8.38 + 2.2 [C] 8.38 + 2.2 [D] 8.38 − 2.2

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### Video Transcript

Find a subtraction expression that is equivalent to the addition expression negative 8.38 plus negative 2.2. Is it A) negative 8.38 minus 2.2, B) negative 8.38 plus 2.2, C) 8.38 plus 2.2, and D) 8.38 minus 2.2.

Adding a negative number is the same as subtracting that same number. This means that negative 8.38 plus negative 2.2 can be rewritten as negative 8.38 minus 2.2. This means that option A negative 8.38 minus 2.2 is the correct answer.

We could check this by evaluating each of the expressions. The answers to the four expressions are negative 10.58, negative 6.18, 10.58, and 6.18. As the answer to the original addition expression negative 8.38 plus negative 2.2 is also negative 10.58, we know that option A is definitely correct.