Translating Sentences into Equations
August 22, 2011
Translating Sentences into Equations
Objective The student will learn to translate
word sentences into equations.
Translating Sentences into Equations
Applications of algebra frequently require
you to translate word sentences
aboutnumbers into equations. Sometimes
you can translate the words in order. Other
times you may need grouping symbols.
Example
Translate the following sentence:
Twice the sum of a number and four is ten.
2 ∙ 𝑛 + 4 = 10
Example
Translate the following sentence:
When a number is multiplied by four and the result is decreased by six, the result is ten.
4𝑥 −6 = 10
Caution
Be careful when the words “less than” are used. You may not be able to translate the words in order.
Three less than the number x is 12.
𝑥 − 3 = 12
Formulas
Sometimes you will need to use a formula in order to write an equation.
4 4
x
Perimeter = 14
Perimeter = the sum of the lengths of the sides
14 = 4 + 4 + 𝑥
14 = 8 + 𝑥
Formulas
a. Choose a variable to represent the number described by the words inparentheses.
b. Write an equation that represents the given information.
Formulas
The distance traveled in 3 hours of driving was 240 km. (Hourly rate)
a. Let r = the hourly rate
b. Formula: rate time = distance
c. 𝑟 ∙ 3 = 240 , or 3𝑟 = 240
Solution 2
The distance traveled in 3 hours of driving was 240 km. (Hourly rate)
a. Let r = the hourly rate
b. The hourly rate is the number of miles traveled in one hour
c. 𝑟 =240
3
Class work
Oral Exercises
P 20: 1-13
Homework
p 20: 2-16 even, p 21: 17-35 odd, p 22: Mixed Review