Activity 4. Writing a Mathematical Expression Directions: Using only one variable, write a mathematical expression for each.

Question

Activity 4. Writing a Mathematical Expression

Directions: Using only one variable, write a mathematical expression for each.

1. Carlo's age in 5 years

2. The total interest earned after one year when Php 200,000 is invested, part at 6% annual interest rate, and the remaining part at 5.5% annual interest rate

3. The distance travelled by a man driving at the rate of 60 kph

4. The percentage of alcohol in a mixture of ½ liter of pure water and x liter of 5% alcohol solution

5. The perimeter of a rectangle whose length is three times the width

6. A three-digit number whose hundreds digit is one-third the tens digit and the tens digits five more than the units digit

7. The total peso value of 30 coins consisting of Php 20 coins and Php 10 coins

Answer 1

The answers are:

1. c + 5, where c is Carlos' current age
2. 11,000 + 1000x, where x is the fraction of the money invested at 6 percent and 0 ≤ x ≤ 1
3. 60h kilometers, where h is the number of hours he has been driving
4. 0.05x ÷ (1 + x), where x is the number of liters of the 5% alcohol solution
5. 128 + 133u, where u is the units digit and u can only be 1 or 4
6. 300 + 10n, where n is the number of 20 peso coins and 0 ≤ n ≤ 30