3x +32 -4x =29
32 -x =29
x =32 -29
x =332 -x =29是为什么3x +32 -4x =2932 +(3x -4x ) =2932 - x =2932 +(3x -4x ) =29，为什么等于32 - x =293x -4x= -x或者你这么理解 32 - 29 = 4x -3x 3 = x