Solving Problems Involving Algebraic Expressions

Solving Problems Involving Algebraic Expressions

LET's REVIEW

Activity 1. Translate Me!

Translate each mathematical expressions into algebraic expressions.

Multiple Select

3. 50 decreased by the product of c and d

• 50 - cd

• cd-50

• 50 + cd

• 50cd

Multiple Choice

4. Six times the number x, increased by 10

• 10x +6

• 6x-10

• 6x+10

Multiple Select

5. Five less than twice a number y

• 5 - 2y

• 5 + 2y

• 2y - 5

• 2y + 5

Steps in Solving Problems Involving Algebraic Expressions

1. Read and understand the problem carefully.

2. Identify the unknown quantity and assign the variable to represent it.

3. solve

• 4. Interpret your solution to answer the question in the problem.

  
  

Example 1.

Durian costs Php x per piece. How many will 3 dozens cost?

Solution:

There are 12 pieces of durian in 1 dozen of durian.

This means that there are 36 pieces of durian in 3 dozens. If x is the cost of

each durian then, Php 36x is the cost of 3 dozens durian.

Example 2.

Mark saves p pesos in his weekly allowance.

a. How much will he saved in 3 weeks?

b. How much is his savings in 4 months?

Solution:

a. He will save 3p. (3 weeks x p pesos)

b. He can save 16p. (4 months x 4 weeks x p pesos)

Example 3.

Ana worked m hours finishing her homework in mathematics. She worked p

hours less on her homework in science. Write an expression that represents:

a. the number of hours she spent finishing her homework in

science; and,

b. the total number of hours she worked for her homework in

mathematics and science.

Multiple Choice

a. the number of hours she spent finishing her homework in

science;

• she worked m – p hours finishing her homework in

  science.

• she worked m + p hours finishing her homework in

  science.

Multiple Select

b. the total number of hours she worked for her homework in

mathematics and science.

• the total time she spent on the two subjects was m + (m - p).

• the total time she spent on the two subjects was m - (m - p).

Multiple Select

Rey is 5 years younger than his sister Roan. If Roan’s age is R, what expression

stands for Rey’s age?

Rey’s age is 5 less than Roan’s age.

Five less than R.

• R – 5.

• 5 - R

• R + 5

• 5R

Multiple Choice

Robert wants to fence his rectangular lot. If the length of the lot is 3 meters longer than its width. What is the perimeter of the of the rectangular lot if its width is y meters?

• 4y + 6 meters

• 4y – 6 meters

• 6y + 4 meters

• 6y – 4 meters

Multiple Select

Rose had ten roses (r) in her garden. During weekends she buys additional roses. Express her total roses in algebraic expression.

• 10r

• 10 – r

• r – 10

• 10 + r

Multiple Choice

In Grade 7- Belardo, there are 15 girls and b boys. Which of the following expression represents the total number of students in the class?

• 15 – b

• b – 15

• 15 + b

• 15b

Multiple Select

There are y carabaos and d ducks in the farm. How many legs are there?

• 2y – 4d

• 4y – 2d

• 2y + 4d

• 4y + 2d

Multiple Choice

Two numbers add up to 10. If one of the numbers is f, what is the other number?

• 10 + f

• f – 10

• 10 – f

• 10f

Multiple Choice

Agnes is q years old. How old she will be in 12 years?

• q – 12

• q +12

• 12 – q

• 12q

Multiple Select

A car travels y kilometers in 1 hour. Express the speed of the car after 4 hours.

• y

• y + 4

• 4y

• y – 2

Multiple Select

Mhackie helps his father feed the chickens in their farm. Each day, a chicken z eats 95 grams of growing mash. Mhackie will prepare a food budget for the chicken. Which of the following algebraic expressions represent the daily food budget for the chickens in the farm?

• 95z

• z – 95

• z + 95

• 95 – z

THANK YOU!