Answer: c= 49/4
Step-by-step explanation:
Lets find that number:
3 < x < 4
that can easily be thought as 3.5
<span>3 < 3.5 < 4
</span>now lets change the decimal to a mix number:
3.5 = 3 + 0.5
= 3 + 5/10
= 3 + 1/2
= 3 1/2
We want to calculate the following

Using the properties of exponents, we have that

So we have

So, if factor 10^-4 on the right side, we have

Note that

Then,

So we have that
Start with

Add 2x to both sides:

Subtract 21 from both sides:

Divide both sides by 5. Since it is positive, we don't have to change the inequality sign:

So, the answer is 