Answer: 
Step-by-step explanation:
Given logarithm expression

We need to write it as a single logarithm expression.
First we need to apply exponent rule of logs to remove 7 and 6 in front of logs.

.
Now, we need to apply product rule of logs
.

Therefore, final answer is 
Answer:
A
Step-by-step explanation:
b must always be greater than 0 since 12b-15 must always be greater than 21. You can simplify the ineqaulity to see things easier; 12b>36. Again, this ineqaulity can be simplified; b>3. A is the closest answer here, but there should be an open interval at 3 for A to be correct.
Answer: 47.86
Step-by-step explanation:
tan x =42/38
tan x= 1.105
x= 47.86
A) f(x)=0.2x
B)f(12)=0.2(12)=2.4 dollars