Algebra I 1 3 Write Expressions Objective The

Algebra I 1. 3 Write Expressions

Objective The student will be able to: translate verbal expressions into math expressions and vice versa.

Vocab • Verbal Model — a real life situation using words as labels and using math symbols to relate the words • Rate — a fraction that compares two quantities measured in different units • Unit Rate — when the denominator of a rate is one

An algebraic expression contains: 1) one or more numbers or variables, and 2) one or more arithmetic operations. Examples: x– 3 3 • 2 n

In expressions, there are many different ways to write multiplication. 1) 2) 3) 4) 5) ab a • b a(b) or (a)b (a)(b) axb

Division, on the other hand, is written as: 1) 2) x ÷ 3

Throughout this year, you will hear many words that mean addition, subtraction, multiplication, and division. Complete the table with as many as you know.

Here are some phrases you may have listed. The terms with * are ones that are often used.

• Translating Verbal Phrases – Examples: • 4 less than the quantity 6 times a number n • 3 times the sum of 7 and a number y • The difference of 22 and the square of a number m – Now Try This One: • The quotient when the quantity 10 plus a number x is divided by 2

Write an algebraic expression for 1) m increased by 5. m+5 2) 7 times the product of x and t. 7 xt or 7(x)(t) or 7 • x • t

3) 11 less than 4 times a number. 4 n - 11 4) two more than 6 times a number. 6 n + 2 5) the quotient of a number and 12.

Which of the following expressions represents 7 times a number decreased by 13? 1. 2. 3. 4. 7 x + 13 7 x - 13 13 - 7 x 13 + 7 x Answer Now

Which one of the following expressions represents 28 less than three times a number? 1. 2. 3. 4. 28 - 3 x 3 x - 28 28 + 3 x 3 x + 28 Answer Now

Write a verbal expression for: 1) 8 + a. 2) The sum of 8 and a The ratio of m to r

Which of the following verbal expressions represents 2 x + 9? 1. 2. 3. 4. 9 increased by twice a number increased by nine twice a number decreased by 9 9 less than twice a number Answer Now

Which of the following expressions represents the sum of 16 and five times a number? 1. 2. 3. 4. 5 x - 16 16 x + 5 16 + 5 x 16 - 5 x Answer Now

Which of the following verbal expressions represents x 2 + 2 x? 1. 2. 3. 4. the sum of a number squared and twice a number the sum of a number and twice the number twice a number less than the number squared the sum of a number and twice the number squared Answer Now

Which of the following expressions represents four less than the cube of a number? 3 1. 4 – x 2. 4 – 3 x 3. 3 x – 4 4. x 3 – 4 Answer Now

• Write an expression – You have a ribbon that is 8 inches long • Suppose you cut a 2 in piece? What would you do to find the remaining length? ? • Suppose you cut a piece n inches? How could you write an expression of the length remaining? ? • Find a Unit Rate – A car travels 110 miles in 2 hours. Find the Unit Rate

• Solve a Multi Step Problem – Your basic monthly charge for cell phone service is $30, which includes 300 free minutes. You pay a fee for each extra minute you use. One month you paid $3. 75 for 15 extra minutes. Final your total bill if you use 22 extra minutes.