Question

Janet bought4/5 of a pound of walnuts. Her family ate 1/3 of a pound. How much is left?

Answer 1

this just wants us to calculate 4/5-1/3

make common denom

4/5 times 3/3=12/15

1/3 times 5/5=5/15

4/5-1/3=12/15-5/15=(12-5)/15=7/15

7/15lb is left

Answer 2

$\frac{4}{5} - \frac{1}{3}$
Make the denominators the same. The easiest way in this case is to find the number they multiply by, which is 15.

Then, whatever you had to multiply for that denominator, you do for the numerator.

$4 \times 3 = 12 \\ 1 \times 5 = 5\\ \\ \frac{12}{15} - \frac{5}{15 } = \frac{7}{15}$
Subtract the top but not the bottom. You can't simplify in this one.