By the definition we must find a **C** and **k** so that for all
**x> k**

**2^x + 17 < C*3^x**

Leave the equation as it is and see if we can deduce what C and k must
look like.

Just divide both sides by **2^x** and we see that we want (it's a
good idea to distinguish what we __want__ from what we __have__

** 1+ (17/2^x)< C*3^x/2^x = C*(3/2)^x**

Now if **k>5** and **x> k**, we get that **2^x> 17**,
hence **1+(17/2^x)** is smaller than **2** for all values of **
x> 5**. Also, for **x> k > 5**
we know that **C*(3/2)^x** is
greater than **C*(3/2)**, so if we take **C=4**, we get
that

** C*(3/2)^x > 4*(3/2)> 2 > 1+(17/2^x)** for all **
x> 5**