а−bа-bа−b+c−dc-dc−d = а - b + c - d x+yx+yx+y-z+tz+tz+t = x + y - z - t m−nm-nm−n-k−tk-tk−t = m - n - k + t t+st+st+s+−p−m-p-m−p−m = t + s - p - m
x+yx+yx+y+y−xy-xy−x = x + y + y - x = 2y a−ba-ba−b-a−ba-ba−b = a - b - a + b = 0 c−dc-dc−d-c+dc+dc+d = c - d - c - d = -2d u+vu+vu+v-v−uv-uv−u = u + v - v + u = 2u
а−bа-bа−b+c−dc-dc−d = а - b + c - d
x+yx+yx+y-z+tz+tz+t = x + y - z - t
m−nm-nm−n-k−tk-tk−t = m - n - k + t
t+st+st+s+−p−m-p-m−p−m = t + s - p - m
x+yx+yx+y+y−xy-xy−x = x + y + y - x = 2y
a−ba-ba−b-a−ba-ba−b = a - b - a + b = 0
c−dc-dc−d-c+dc+dc+d = c - d - c - d = -2d
u+vu+vu+v-v−uv-uv−u = u + v - v + u = 2u