The area of Gabriel's rectangular backyard is square feet. A rectangular pool in the backyard has an area of square feet.
Which expression represents the area of the backyard, in square feet, that is not covered by the pool?
Show answer & explanation
Answer: C
- 1. Uncovered area = backyard area − pool area: .
- 2. Distribute the negative: .
- 3. Combine like terms: .
- 4. Check with : , and .
: Subtracts only . The subtraction must apply to all three terms of the pool's area.
: Changes the sign of but not of . Subtracting 150 gives −150.
: Correct. (A.10A).
: Adds the two areas instead of subtracting the pool from the backyard.
"Not covered" means subtract. Put the whole polynomial being subtracted in parentheses and change the sign of each of its terms.