Such as: a-(b-c+d)=a-b+c-d
When solving the equation, the shift term should be changed-to move an item on one side of the equal sign to the other side of the equal sign, the sign must be changed:
For example, 5x-6=4x+8
Transposition: 5x-4x=8+6
Unequal signs in inequality change direction;
When both sides of inequality are multiplied by a negative number or divided by a negative number, the direction of inequality should be changed:
Such as: -2x > 4? ，(- 1/2)x & gt； four
? x & lt-2 ? , ? x & lt-8