1. how is being able to find the least common
multiple when adding and subtracting
fractions?

Step-by-step

For relatively small denominators, the easiest way is to multiply the two denominators AND divide by the highest common factor (HCF).

For example, adding 5/24+3/16

24*16 = 384  

(use a calculator if necessary, for mental calculation, 24*16=20^2-4^2=400-16=384 ).

The highest common factor (HCF) is 8, since 24/8=3, 16/8=2, 3 and 2 do not have any more common factors, so it is the HCF.

The lowest common multiple (LCM) is then 384/8 = 48

For someone good at factoring, we see that the factors are:

24={2^3,3}

16={2^4} = {2^3,2}

so the LCM is either 16*3=48, or 24*2=48.

So,

We can visualize skydivers A, X, and B as corresponding to three coordinates -2.5, 0, and 0.5, respectively.

To find the distance from A to B, we can just take the absolute value of the different between their coordinates.

|-2.5 - 0.5| <-- this is the expression

|-2.5 - 0.5| = |-3| = 3 <-- this is the distance