x = [1 2 3 4 5 6]; y = [11 61 111 161 211 261]; m=x(:)\y(:);
You can find the doc if you look for mldivide.
edit: thanks for the correction/addition from Star Strider (Converting to an array with (:) always works, while my original solution with a transposition only works if the input is a row vector. I also referred to mrdivide instead of mldivide.)