Skip to main content
Ch. 1 - Equations and Inequalities
Blitzer - College Algebra 8th Edition
Blitzer8th EditionCollege AlgebraISBN: 9780136970514Not the one you use?Change textbook
Chapter 2, Problem 17

Including a 10.5% hotel tax, your room in San Diego cost \$216.58 per night. Find the nightly cost before the tax was added.

Verified step by step guidance
1
Let the nightly cost before tax be represented by \(x\).
The hotel tax is 10.5%, which means the total cost after tax is the original cost plus 10.5% of the original cost. This can be written as \(x + 0.105x\).
Combine like terms to express the total cost as \$1.105x$.
Set up the equation \(1.105x = 216.58\) to represent the total cost including tax.
Solve for \(x\) by dividing both sides of the equation by 1.105: \(x = \frac{216.58}{1.105}\).

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
3m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Percentage and Percent Increase

A percentage represents a part of a whole expressed per hundred. Percent increase involves adding a certain percentage to an original amount, which is essential here to understand how the tax increases the base price.
Recommended video:

Finding the Original Amount Before Tax

To find the original price before tax, you divide the total cost by one plus the tax rate expressed as a decimal. This reverses the effect of the added percentage and helps isolate the base price.
Recommended video:
5:50
Asymptotes of Hyperbolas

Decimal Conversion of Percentages

Percentages must be converted to decimals for calculations by dividing by 100. For example, 10.5% becomes 0.105, which is used in multiplication or division to find amounts related to the percentage.
Recommended video:
4:47
The Number e