Topic
Expanding brackets 1.
Addition and subtraction of multi-term expression.
Expanding brackets 1.
If a multi-term expression appears in a multi-term expression with positive sign, expanding the brackets can be performed by just removing them, with the signs of the terms remaining unchanged.
If there is a negative sign in front of a multi-term expression, when we expand the brackets then all the signs of the terms will be changed to their opposites.