A student claims that the equation �ã-x=3 has no solution, since the square root of a negative number does not exist.
sqrt (-x)=3
square both sides
-x=9
x=-9
Try it in the original...
sqrt (-(-9))= sqrt (9)=3
square both sides
-x=9
x=-9
Try it in the original...
sqrt (-(-9))= sqrt (9)=3