For 104 the base is 10 and the exponent is 4.
4.2 × 104
The two are related. The answer could be base 2, exponent 18 or base 8, exponent 6 or base 10, exponent 5.4185 or base 262144, exponent 1 or base 68,719,476,736 and exponent 0.5
8 × 104
1.9742 x 104
2 x 104
104
7.8493 x 104
The base of an exponent is the main number. For example in 56 the number 5 is the base and 6 is the exponent.
10x 10 is Base & x is exponent
If you have ab then a is the base and b the exponent
4 is the base, 2 is the exponent.
The base could be 11 and the exponent 2, giving 112 But, it could equally be base = 14641, and exponent = 0.5, or base = 10, and exponent = 2.082785 (approx)