Subtract the fractions and write your answer in lowest terms.

Question

four-fifths – three-eighths
(1 point)
Responses

one over forty
Image with alt text: one over forty

one and seven over forty
Image with alt text: one and seven over forty

seven over ten
Image with alt text: seven over ten

seventeen over forty

Answer 1

To subtract the fractions four-fifths and three-eighths, we need to find a common denominator.

The multiples of 5 are: 5, 10, 15, 20, 25, 30, 35, 40, ...
The multiples of 8 are: 8, 16, 24, 32, 40, ...

The least common multiple (LCM) of 5 and 8 is 40. So, we can rewrite the fractions with the common denominator of 40:

four-fifths = 32/40
three-eighths = 15/40

Now, we can subtract the fractions:

32/40 - 15/40 = (32 - 15)/40 = 17/40

Therefore, the answer is seventeen over forty.

Answer 2

If Sandy’s cookie recipe calls for one-third cup of brown sugar and she increases it by two-ninths of a cup, how much brown sugar does she use?
(1 point)
Responses

seven-ninths cup
Image with alt text: seven-ninths cup

start fraction 5 over 9 end fraction cup
Image with alt text: start fraction 5 over 9 end fraction cup

start fraction 4 over 9 end fraction cup
Image with alt text: start fraction 4 over 9 end fraction cup

one-ninth cup