7) 1/4 * 3/5 we use direct multiplication of fractions and get:
1/4 * 3/5 = (1 * 3) / (4 * 5) = 3 / 20
which is already in simplest form
8) 3 1/2 * 4 2/3 These are mixed numbers, so we first convert them into improper fractions and then multiply as shown below:
3 1/2 = 6/2 + 1/2 = 7/2
and
4 2/3 = 12/3 + 2/3 = 14/3
Now we multiply these fractions:
7/2 * 14/3 = (7 * 14) / (2 * 3) = 98/6 where we can cancel a common factor of "2"from numerator and denominator, leading to: 49/3 and in mixed number form = 16 1/3
9) 2 * 5/6 = 2/1 * 5/6 where we wrote the integer "2" as the fraction 2/1 in order to be able to use the convention for multiplying fractions. Then:
2 * 5/6 = (2 * 5) / (1 * 6) = 10/6 here we can again simplify a common factor of 2 in numerator and denominator, leading to: 5/3
Then 2 * 5/6 = 5/3