Algebra-1

The answer is A. add 18 to both sides.

When solving an equation, we want to isolate the variable on one side by performing the inverse operation of the operation being performed on the variable.

In the given equation, the variable "x" is being subtracted by 18. To isolate "x," we need to perform the inverse operation, which is adding 18. By adding 18 to both sides of the equation, we maintain the equality of the equation.

Adding 18 to both sides gives ...