How do you subtract #11/12 - 11/14#?

Question

692 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2016-09-09T21:30:30

#11/84#

Before we can subtract the numerators, the denominators have to be the same, so we are working with the same sized portions.

What is the LCD?

An obvious answer is #12 xx14#, but this will be too big because both 12 and 14 are even, so they share a factor of 2.

Starting with #12xx14" "# divide them both by 2.

Let's try #2(6xx7) = 84" "# 6 and 7 do not have a common factor

#11/12 xx7/7 -11/14 xx 6/6 #

=#(77-66)/84#

=#11/84#