Kiara asked in Science & MathematicsMathematics · 10 years ago

# How to do 12 3/8 - 7 1/2?

I have figured out how to add these type of fractions but how do you subtract?!

On adding you cross multiply.

On subtracting this, do you still cross mulitply? PLEASE EXPLAIN!!!

A. 4 7/8

B. 5 7/8

C. 5 1/3

D. None of the above

Relevance
• 10 years ago

12 3/8 - 7 1/2

There are multiple ways you could do this, but here is one way.

8x12+3 = 99/8 (99/8 is the exact same thing as 12 and 3/8 but I am just putting it all on one fraction)

2x7+1 = 15/2 ( same as 7 and 1/2 as well)

99/8 - 15/2

Next I would put the fractions on the same denominator, and so I am going to put them both on 8 as that seems the easiest.

15x4/2x4

= 60/8

99/8 - 60/8

And so now you would not minus the denominators, but only the numerators. And so you would do 99-60/8 = 39/8

I see that the choices you have are all mixed fractions (meaning whole numbers and fractions together, unlike 39/8) and so I am going to put it back into a mixed fraction. 8 goes into 39 4 times, and there is 7 leftover. And so, the answer would be 4 7/8 (The letter A)

Hope this made sense..

• 10 years ago

12 3/8 - 7 1/2 is 12 3/8 - 7 4/8 or 11 11/8 - 7 4/8 = 4 7/8.

• 4 years ago

exchange the hardship-unfastened denominator to 24. then you definately get 9/24 + 14/24 + forty/24 9+14+forty = sixty 3 so then you definately've sixty 3/24 the two a form of are divisible via 3, so which you get 21/8 and to make that a suitable fraction then you have 2 and 5/8