Question 188604
Here is a tip:

No one is going to solve all these questions if you place them all together in a single post.

Post each question separately.

I will do log (7x + 3) = 2 only.

Here, the base = 10 and exponent = 2.

We isolate 7x + 3 on one side of the equation.

10^2 = 7x + 3

100 = 7x + 3

100 - 3 = 7x

97 = 7x

97/7 = x

I will let you finish.  To do so, divide 97 by 7 and then round off to the nearest hundredths.  Can you take it from here?