well the question is: (sorry don't know how to type math)

lim2x+3

x->-∞ 5x+7

well the answer key says 2/5 but i get -2/5... i looked up online which told me to get rid of the negative by replacing it with u so i did that and still got the same answer.

This is what I did...

lim-2(-x)+3

x->-∞ -5(-x)+7

- lim-2u+3

u->∞ -5u+7

- limu(-2 + (3/u))

u->∞ u(-5 + (7/u))

-u(-2)

u(-5)

-2/5

this is from instructions online what i normally do is just :

lim2x+3

x->-∞ 5x+7

)

x(2 + (3/-∞)

x(5 + (7/-∞))

and this gets me like ∞/∞????

I don't get it what am I doing wrong???