diff --git a/lib/matrix_check_sum.rb b/lib/matrix_check_sum.rb
index dc2a66b..91278fa 100644
--- a/lib/matrix_check_sum.rb
+++ b/lib/matrix_check_sum.rb
@@ -2,6 +2,30 @@
 # whether the sum of each row matches the sum of corresponding column i.e. sum
 # of numbers in row i is the same as the sum of numbers in column i for i = 0 to row.length-1
 # If this is the case, return true. Otherwise, return false.
+require 'pry'
 def matrix_check_sum(matrix)
-  raise NotImplementedError
+  row_sum = 0
+  column_sum = 0
+
+  matrix.length.times do |i| # the # of rows there are
+    matrix[i].length.times do |j| # the # of columns in this row
+      row_sum += matrix[i][j] #row 0 column 0, row 0 column 1, row 0 column 2
+      column_sum += matrix[j][i]
+    end
+    if row_sum != column_sum
+      return false
+    end
+  end
+  return true
 end
+
+#Space Complexity:
+# O(n + m) where n is the length/size of the row, and m is length/size of the column.
+# Two variables are defined, and the space that their values take up will increase
+# based on the row + column value.
+#
+#Time Complexity:
+# O(n * m) where n is the length of the row, and m is the length of the column.
+# There are two loops in this solution. In the worst case the first will run
+# n times and the second will run m times.
+#