Subtracting fractions with whole numbers doesn't differ much from adding fractions with whole numbers (just remember how to subtract integers correctly).
Indeed, suppose we want to subtract whole number m from fraction qn.
It is known that whole number m can be represented as fraction 1m.
Now, m−qn=1m−qn=qmq−qn=qmq−n.
Formula for subtracting fractions with whole numbers: m−qn=qmq−n.
Example 1. Find 3−76.
Let's solve it step-by-step:
3+76=13−76=1⋅73⋅7−76=721−76=715.
If you need mixed number, convert 715 into midex number: 715=271.
Answer: 715=271.
Next example.
Example 2. Find −9−813.
Let's use direct formula:
−9−813=8−9⋅8−13=8−72−13=−885.
Convert to mixed number if needed: −885=−1085
Answer: −885=−1085.
Next example.
Example 3. Find −49−3.
−49−3=−49−1⋅43⋅4=−49−412=4−9−12=−421.
Convert to mixed fraction if needed: −421=−541.
Answer: −421=−541.
Now, it is time to practice.
Exercise 1. Find 2−76.
Answer: 78=171.
Next exercise.
Exercise 2. Find 529−9.
Answer: −516=−351.
Next exercise.
Exercise 3. Find 5−(−897).
Answer: 8135=1687.
