Okay, I'll type as fast as I can!

1) Change to "improper fractions" 4 is because 12/3= 4. "4 and 1/3" is . Similarly 3 is because 21/7= 3. "3 and 6 sevenths" is .

So "4 and 1/3 minus 3 and 6/7" is . To add or subtract two fractions you need a "common denominator". Since 3 and 7 have no factors in common, we can just multiply the numerator and denominator of the first fraction by 7, , and multiply the numerator and denominator of the second fraction by 3, .

Now the problem is and we can simply subtract the numerators: .