There is only one unknown, the degree of the unknown is 1, and both sides of the equal sign are algebraic expressions. Such an equation is called a linear equation.

If an equation contains a denominator (the denominator is a number), then the denominator should be removed first.

After removing the denominator, if there are similar items, the similar items are merged first (if the similar items are on both sides of the equal sign, the items are moved first). For example: x+ 1=-2x), and the final coefficient is 1.

The constant term is usually on the right side of the equal sign, and the principal term is usually on the left side of the equal sign.