diff --git a/cachematrix.R b/cachematrix.R
index a50be65aa44..49a7f595922 100644
--- a/cachematrix.R
+++ b/cachematrix.R
@@ -1,15 +1,30 @@
-## Put comments here that give an overall description of what your
-## functions do
-
-## Write a short comment describing this function
+## functions for creating a cacheable matrix and solving it.
 
+## creates a cacheable matrix
 makeCacheMatrix <- function(x = matrix()) {
-
+        inv <- NULL
+        set <- function(y) {
+                x <<- y
+                inv <<- NULL
+        }
+        get <- function() x
+        setinv <- function(y) inv <<- y
+        getinv <- function() inv
+        list(set = set, get = get,
+             setinv = setinv,
+             getinv = getinv)
 }
 
 
-## Write a short comment describing this function
-
+## solves for the inverse of a cacheable matrix (or uses the cached solution)
 cacheSolve <- function(x, ...) {
-        ## Return a matrix that is the inverse of 'x'
+        inv <- x$getinv()
+        if(!is.null(inv)) {
+                message("getting cached data")
+                return(inv)
+        }
+        data <- x$get()
+        inv <- solve(data, ...)
+        x$setinv(inv)
+        inv
 }