Answer:
D. Kari added the compatible numbers –12 and 4.
Explanation:
Kari estimated the quotient of Negative 12 and one-fifth divided by 4 and two-fifths to be –8. Which best describes her error?
-12 1/5 ÷ 4 2/5 = -8
A. Kari multiplied the compatible numbers –12 and 4.
-12 * 4 = 48
A. Is not correct
B. Kari found that the quotient of a negative number and a positive number is negative.
Example:
-a/a = -1
The rule is right
C. Kari found that the quotient of a positive number and a negative number is positive.
a/-a = -1
The rule is wrong
D. Kari added the compatible numbers –12 and 4.
= -12 + 4
= -8
Therefore, Kari error was that she added the compatible numbers –12 and 4.