[tex] \frac{5}{8} - \frac{2}{5} [/tex]
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.
[tex] \frac{5*5}{8*5} - \frac{2*8}{5*8} [/tex]
Third, multiply.
[tex] \frac{25}{40} - \frac{16}{40} [/tex]
Fourth, since the denominators are the same now, we can combine them.
[tex] \frac{25-16}{40} [/tex]
Fifth, subtract '25 - 16' to get 9.
[tex] \frac{9}{40} [/tex]
Since [tex] \frac{9}{40} [/tex] is already in the simplest form, it is your answer.
Answer as fraction: [tex] \frac{9}{40} [/tex]
Answer as decimal: [tex]0.225[/tex]
