Learn Sudoku

"Analysis consists of two methods namely candidate elimination and the what if. I will not be showing the what if to you because i don't like it. It's slow progress and i don't like to erase that much. the candidate elimination. the method for candidate elimination I'm showing now is the matched pair method.This method happens when a pair of numbers are the only possible answer to two cells. Take a look at the picture. I have concluded(with the help of cross hatching) that 7 and 8 can only be in two places in the lower left region(i filled both in) . The two cells which 7 and 8 can be in is in the same column, thus it cannot be elsewhere in the column. There is two other blank cells in this column and the missing numbers is 9 and 3. We can see that 3 can not be in the 'middle' open cell. This means 3 is in the top cell(marked green) and 9 is in the 'middle' cell. Candidate elimination can also be used with three number in three cells. *note: Candidate elimination is note the fastest nor easiest method for for finding the green cells answer. That is why one must first scan before analyzing . I will try to find a better example.this one is almost like the candidate elimination i showed you in the previous step(its called deriving certainty from uncertainty). Take a look at the picture below.In the center region. There is only two possible places for the 7(and 2). There is three places for the seven in the middle right region , but can not be in the middle ones because 7 is reserved by the center region thus there is only one place let for the seven in the middle right region."