Josefina started to solve for x in the equation
3.5 = 1.9 – 0.8|2x – 0.6| using the steps below:
3.5 = 1.9 – 0.8|2x – 0.6|
1.6 = –0.8|2x – 0.6|
–2 = |2x – 0.6|
why did josefina stop at step 3?

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

true? is that what you're asking or do you mean something else?