Question

Work out 5/8−2/5 Give your answer in its simplest form.

Answer 1

`(5)/(8) - (2)/(5)`

First, find the LCD (least common denominator) of the two fractions.
List the multiples of each denominator and find the one that is common.
Multiples of 8: 8, 16, 24, 32, 40
Multiples of 5: 5, 10, 15, 20, 25, 30, 35, 40
40 is your LCD.

Second, what can you divide by to make the denominators of each fraction '40'? Whatever you do to the bottom you must do to the top.

`(5*5)/(8*5) - (2*8)/(5*8)`

Third, multiply.

`(25)/(40) - (16)/(40)`

Fourth, since the denominators are the same now, we can combine them.

`(25-16)/(40)`

Fifth, subtract '25 - 16' to get 9.

`(9)/(40)`

Since
`(9)/(40)` is already in the simplest form, it is your answer.

Answer as fraction:
`(9)/(40)`
Answer as decimal:
`0.225`