how many feet

if i am make 200 invites that are 5x7 how many feet of paper do i need

Well, first that depends on what unit the 5x7 is. I'm assuming that is in feet.

Then, find 5*7, which is 35. So each invite is 35 feet squared.
Then, multiply this by 200 to find the total square feet of paper needed.
200*35

=7,000 square feet of paper total (only if all your starting units were feet.)

Guest:

if i am make 200 invites that are 5x7 how many feet of paper do i need

I think 5 by 7 inches would be more realistic Kitty. (Don't forget to do reasonableness checks )

200*5*7 = 7000 inches ²

12*12 = 144 square inches in a square foot

7000/144 = 48.61repeater

So you will need about 49 square feet of paper.