Question

What were Mortie's errors? Check all that apply.

a) He should have made all the signs positive.
b) He should have found the common denominator, 12.
c) He should have subtracted 4/5 from 3/4.
d) The answer should be 1/12.

Answer 1

Mortie's errors include not making all the signs positive and not finding the common denominator.

Step-by-step explanation:

Mortie's errors include:

• He should have made all the signs positive. When subtracting fractions, it is important to change the signs of the second fraction and then perform the subtraction. In this case, Mortie should have changed 4/5 to -4/5 before subtracting it from 3/4.
• He should have found the common denominator, 12. When subtracting fractions, if the denominators are different, you need to find a common denominator before performing the subtraction. In this case, the common denominator is 12 because both 4 and 5 divide evenly into 12. Mortie should have expressed 3/4 and -4/5 with denominators of 12 before subtracting them.

Therefore, options a) and b) are the correct answers.