Question

Help ! its not a test i just don't understand!!

Answer 1

An important rule before subtracting fractions, you must first make them have a common denominator. The common denominator is the LCM (Least Common Multiple) of the two different denominators.

You may use this formula:

`(a)/(b)=((a)((c)/(b)))/(c)`

We get,

a.) 9/12 - 1/2 ; The LCM of 12 and 2 is 12.

`(9)/(12)-(1)/(2)=\text{ }(9)/(12)-((1)((12)/(2)))/(12)=\text{ }(9)/(12)-((1)(6))/(12)=(9)/(12)-(6)/(12)`
`(9)/(12)-(6)/(12)=(3)/(12)`

Therefore, the difference of 9/12 - 1/2 is 3/12. You shade letter B.