1) (3x + y) - (-x - 4y) = 3x + y + x + 4y = 4x + 5y
2) (x + 6y) - (8x - 7y) = x + 6y - 8x + 7y = -7x + 13y
3) (m + n) - (m - n) = m + n - m + n = 2n
4) (m + 3) - (6m + 5) - (m - 1) = m + 3 - 6m - 5 - m + 1 = -6m - 1
5) (x - y) + (x - y) - (2x + y) = x - y + x - y - 2x - y = -x - y
6) (0.2x - 3) - (x - 2) - (0.4x - 1) = 0.2x - 3 - x + 2 - 0.4x + 1 = -1.2x - 0.
1) (3x + y) - (-x - 4y) = 3x + y + x + 4y = 4x + 5y
2) (x + 6y) - (8x - 7y) = x + 6y - 8x + 7y = -7x + 13y
3) (m + n) - (m - n) = m + n - m + n = 2n
4) (m + 3) - (6m + 5) - (m - 1) = m + 3 - 6m - 5 - m + 1 = -6m - 1
5) (x - y) + (x - y) - (2x + y) = x - y + x - y - 2x - y = -x - y
6) (0.2x - 3) - (x - 2) - (0.4x - 1) = 0.2x - 3 - x + 2 - 0.4x + 1 = -1.2x - 0.