2. Dismantle the bracket: firstly dismantle the bracket, then dismantle the bracket, and finally dismantle the bracket.
3. Move the term: move all terms containing unknowns to one side of the equation and all other terms to the other side of the equation.
4. Merge similar items: Add the coefficients of similar items by using the law of multiplication and distribution, and the obtained results are taken as coefficients, and the letters and indexes remain unchanged.