His point with the Bongard problems is that you cannot solve them in such a way—whereas e.g. solving a math equation could be done by just executing some known algorithm for solving it, there’s no fixed algorithm that you could apply to solve a Bongard problem.
If we are to be pedantic, I said that solving a math equation can be done in such a way, which can arguably be interpreted as “there exists at least one math equation that can be solved in such a way”.
That’s only true of some equations.
If we are to be pedantic, I said that solving a math equation can be done in such a way, which can arguably be interpreted as “there exists at least one math equation that can be solved in such a way”.