Answer:
The correct answer is option D: 
Step-by-step explanation:
Given:
log(y)= 3.994
Solution:
A logarithm base b of a positive number x satisfies the following definition:

For 
Also if no base b is indicated, the base of the logarithm is assumed to be 10
.
Thus, in log(y)= 3.994 base b is not indicated. so its base is assumed to be 10
now

Then

Answer:
no solution
Step-by-step explanation:
1.4-5-2-3=7-6
2.-1-2-3=7-6
3.-3-3=7-6
4.-6=7-6
5.-6=1
6.since -6=1 is false, there's no solution
answer is A, if its not A then B