In a precalculus course I want to give the students an exercise to solve a system of equations. If the system is singular there are (infinitely) many correct answers. As an oversimplified example, say the question is: Find a solution to the equation x+y=0. Then some correct answers are 0,0 or -1,1 or -2,2 or ... So the student would enter two numbers, and then moodle would have to check to see whether they work.

I have tried the calculated question type but there the answer is always a number whereas here it would be a Boolean true/false.

Can this be done in moodle?