-1
-2
-99 and 146
-125
Any two numbers that when multiplied, equal 8^2 (64). So, 2 and 32 work. So do 1 and 64. And 4 and 16. And .5 and 128
The numbers are 1 and 10.
10
266
79
-1540
99
6 and -5
-66
-8 and -15
-3, -6
15 and 8
Two (or four) digits added together cannot equal 42. Two-digit numbers multiplied together cannot equal 82.