Rene Descates discovered it in the 17th century
Chat with our AI personalities
3*-7=29
3+3=6 add get answer who asks these things!
They are equations that involve many steps to find the solution.
The first step is usually to solve one of the equations for one of the variables.Once you have done this, you can replace the right side of this equation for the variable, in one of the other equations.
They are equations in which you have to use more than more function to solve the problem.