621−143=
Let's work through the problem:
Step 1: Convert to improper fractions.
The mixed number is converted to an improper fraction as follows:
Multiply the whole number 6 by the denominator 2: .
Add the numerator 1: .
The improper fraction is .
The mixed number is converted to an improper fraction as follows:
Multiply the whole number 1 by the denominator 4: .
Add the numerator 3: .
The improper fraction is .
Step 2: Find a common denominator.
The denominators are 2 and 4. The least common denominator is 4.
Step 3: Adjust fractions to have the common denominator.
needs to be adjusted to have a denominator of 4:
Multiply both the numerator and the denominator by 2: .
Step 4: Perform the subtraction.
Subtract from :
.
Step 5: Convert the improper fraction back to a mixed number.
Divide the numerator by the denominator:
with a remainder of 3.
The mixed number is .
Therefore, the solution to the problem is .