<h3>Answer:</h3>
A. (0,0) is a solution to n=m and to n=4m.
<h3>Step-by-step explanation:</h3>The equations can be solved by any of the usual means. Using substitution, we have ...
... m = n = 4m
... m(4 -1) = 0 . . . . subtract the left side
... m = 0 . . . . . . . . divide by 3
... n = m = 0
The solution is (m, n) = (0, 0).