Odpowiedź :
4xy -7x + y - 9xy - 2x + 5y = -5xy - 9x + 6y
4 – (2x – 3) + (5x – 2) = 4 - 2x + 3 + 5x - 2 = 3x + 5
5x + 3 (-4x+1) – 4 (2x – 3) = 5x + 3 - 4x + 1 - 4 + 2x - 3 = 3x - 3
-9 – (3x + 6) + 5 (x – 3) = -9 -3x - 6 + 5 + x - 3 = -2x - 13
-8x + (-2x + 5) – 4 (-2x + 1) = -8x -2x + 5 - 4 - 2x + 1 = -12x + 2