What is the difference of 5 and 2/5 ? show your work

WRite 5 as a fraction with a denominator 5 -  that is  25/5

So 5 - 2/5

= 25/5 - 2/5

= 23/5

or 4 3/5  as a mixed number

hello from mrbilldoesmath!

answer:

a(n) - a(n-1) -3

discussion:

this ones a bit interesting. given a(n) = 5 - 3n consider this:

a(n-1) = 5 - 3(n-1)

          = (5 - 3n) + 3             => but a(n) = 5 - 3n, the first term

          = a(n)   + 3                 => subtract 3 from both sides

a(n-1) -3 = a(n)  

or

a(n) - a(n-1) -3

you,

mrb