2 2 7*m - n + 49*m - n
7*m - n + 49*m^2 - n^2
/ n\ / 1 n\ 1*|m - -|*|m + - + -| \ 7/ \ 7 7/
(1*(m - n/7))*(m + (1/7 + n/7))
-n - n^2 + 7.0*m + 49.0*m^2
(-n + 7*m)*(1 + n + 7*m)