12) Todd factored the expression below. What mistake(s) did he make?
-24xy – 54x
-2(12xy – 27x)

-24xy - 54x

-2x(12y + 27)

0r

-24xy - 54x

-2(12xy + 27x)

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

based on context clues you gave i'm assuming the answer would be c.