diff --git a/cachematrix.R b/cachematrix.R
index a50be65aa44..40956cd6690 100644
--- a/cachematrix.R
+++ b/cachematrix.R
@@ -1,15 +1,54 @@
-## Put comments here that give an overall description of what your
-## functions do
-
-## Write a short comment describing this function
-
+## stores a matrix and its inverse
 makeCacheMatrix <- function(x = matrix()) {
-
+  
+  #initialize variables
+  inv <- NULL
+  
+  
+  #create 4 functions:
+    #1. set matrix - stores the matrix and wipes out the cache
+    setmatrix <- function (y) {
+      inv <<- NULL
+      x <<- y
+    }
+  
+    #2. get matrix - returns the stored matrix (so you can assign the matrix, plus functions elsewhere) 
+    getmatrix <- function() x
+  
+    #3. set inv    - sets the inverse cache to whatever you tell it
+    setinv <- function (inverseval) {
+        inv <<- inverseval 
+    }
+  
+    #4. get inv    - just returns the cached inv
+    getinv <- function () inv
+  
+    #wrap the 4 functions up into a list
+    list(setmatrix= setmatrix,
+         getmatrix= getmatrix,
+         setinv   = setinv,
+         getinv   = getinv)
+  
 }
 
 
-## Write a short comment describing this function
 
+## Returns a matrix that is the inverse of 'x'
 cacheSolve <- function(x, ...) {
-        ## Return a matrix that is the inverse of 'x'
+  
+      #test if x$getinv is null
+       if(is.null(x$getinv()) ) {
+           #if so, get the matrix itself...
+           matr <- x$getmatrix()
+           # then solve for the inverse
+           inv  <- solve(matr)
+           
+      #if it's not null
+      } else {
+          #just grab the cached inverse
+           inv <- x$getinv()
+      }
+      
+    return(inv)
+  
 }