<h2>A.</h2>
So let's break down this sentence (Let n = unknown number):
- "A number is doubled and then 1 is added to it"; Remember that double means multiplied by 2. With this sentence, we can determine that "2n + 1" is a part of the equation.
- "The answer is divided by 5, and then increased by 16"; The "answer" they refer to is "2n + 1" from the prior sentence. Since this is divided by 5 and <em>then</em> added by 16, we can determine that
is a part of our equation.
- "The final result is 18"; This means that the prior part of the equation is equal (=) to 18. <u>With this info, our full equation is
</u>
Now, let's solve our prior equation found in A. To solve for the unknown number, n, we need to isolate the variable onto 1 side of the equation. Firstly subtract both sides by 16 to cancel out the + 16 on the left side:
Next, multiply both sides by 5 to cancel out the division on the left side:
Next, subtract both sides by 1 to cancel out the + 1:
Lastly, divide both sides by 2 to cancel out the multiplication:
<u>In short, the number is 9/2 or 4.5.</u>