3a-7b-6a+8b= -3a + 1b = -3a + b;3(4x+2)-6= 12x + 6 - 6 = 12x;10x-(3x+1)+(x-4)= 10x - 3x - 1 + x - 4 = 7x - 5;2(2y-1)-3(y+2)= 4y - 2 - 3y - 6 = y - 8.
3a-7b-6a+8b= -3a + 1b = -3a + b;
3(4x+2)-6= 12x + 6 - 6 = 12x;
10x-(3x+1)+(x-4)= 10x - 3x - 1 + x - 4 = 7x - 5;
2(2y-1)-3(y+2)= 4y - 2 - 3y - 6 = y - 8.