Lemma
EasyWrite a proof
Gilbert Strang, Calculus, 3rd edition (Wellesley-Cambridge Press; MIT OpenCourseWare RES.18-001) §10.1 The Geometric Series, #9 · Calculus · Series

From the fact that every … goes evenly into a power …

From the fact that every goes evenly into a power minus a smaller power, show that all primes except 2 or 5 go evenly into 9 or 99 or 999 or .

~5 minWritten answer · check your work with Lemma

Gilbert Strang, Calculus, 3rd edition (Wellesley-Cambridge Press; MIT OpenCourseWare RES.18-001) · §10.1 The Geometric Series, #9

Stuck? A gentle nudge

No hints for this one.

Something off?
Workspace
Your working

Check your full solution

Upload photos of your handwritten work or a PDF, and Lemma will read it and tell you whether it's right — and where it first goes wrong if not.

Sign in to have your work checked. It's free.