Помогите пожалуйста с математикой

694.
$1)3x + y + x + 4y = 4x + 5y \\ 2)x + 6y - 8x + 7y = - 7x + 13y$
$3)m + n - m + n = 2n$
$4)m + 3 - 6m - 5 - m + 1 = \\ - 6m - 1$
$5)x - y + x + y - 2x - y = \\ - y$
$6)0.2x - 3 - x + 2 - 0.4x + 1 = \\ - 1.2x$
695.
$1)3a - 3b - 2a - 2b = \\ a - 5b$
$2)4x + 4y + 10x - 5y = \\ 14x - y$
$3)2.4c - 7.2d - 2.6c + 1.3d = \\ - 0.2c - 5.9d$
$4) - \frac{1}{4} m - \frac{3}{4} n- \frac{3}{4} m - \frac{1}{4} n = \\ - m - n$
696.
$3.5a + 7 + 1.5a - 9 = \\ 5a - 2 = 5 \times ( - 0.8) - 2 = \\ - 4 - 2 = - 6$
$2)10.5 - 14b - 5.7 + 8b = \\ 4.8 - 6b = 4.8 - 6 \times 1.3 = \\ 4.8 - 7.8 = - 3$
$3) - 4c - 6 + 7c + 5 = \\ 3c - 1 = 3 \times 7 - 1 = 20$