An Equation with two operations is known as Two Step Equation, likewise an equation with more than one operations or multiple operations is termed as Multi-Step Equations.
This name is used because in order to solve the equation you have to use multiple steps. For example in an equation involving addition and squaring you have two perform two operations in their correct order to get to the answer. So for multiple operations, you have to perform multiple steps to reach at the answer.
Most of the equations we deal in Math are multi-step equations.
