Answer:
They are thinking about either 63 or -63
63 multiplied by -63 is equal to -3969
Explanation:
The multiples of 63.
63,126,189,252,315
The factors of 63
1,3,7,9,21,63
As we can see, 63 is common, so is -63 if we go to the negative side.
So we multiply 63 and -63 and we get -3969
63 multiplied by -63 is equal to -3969