NOTES # Writing algebraic expressions

WHAT OPERATION? Add Example: n + 6 N plus 6 The sum of n and 6 6 added to n N increased by 6 Subtract Example: n -6 N minus 6 The difference between n and 6 6 subtracted from n 6 less than n Multiply Example: 6n N time 6 The product of n and 6 6 multiplied by n Divide Example: n ÷6 N divided by 6 The quotient of n and 6 6 equal shares of n

Problem: Ms. Jensen likes to divide her class into groups of 2. Use mathematical symbols to represent all the students in her class. Solution: Let g represent the number of groups in Ms. Jensen's class. Then 2 · g, or 2g can represent "g groups of 2 students".

WRITE EACH PHRASE AS AN ALGEBRAIC EXPRESSION Phrase The sum of nine and eight The sum of nine and a number

WRITE EACH PHRASE AS AN ALGEBRAIC EXPRESSION Phrase 1) Nine increased by a number x 2) Fourteen decreased by a number p 3) Seven less than a number t 4) The product of 9 and number n 5) Thirty-two divided by a number y

WRITE EACH PHRASE AS AN ALGEBRAIC EXPRESSION Phrase Expression 1) Nine increased by a number x9 + x 2) Fourteen decreased by a number p14 - p 3) Seven less than a number tt - 7 4) The product of 9 and number n9n 5) Thirty-two divided by a number y32/y

WRITING EXPRESSIONS FROM WORD PROBLEMS A small company has $1000 to distribute to its employees as a bonus. How much money will each employee get? Let e represent the number of employees in the company. The amount of money each employee will get is represented by the following algebraic expression: 1000/e

EXAMPLE An electrician charges $45 per hour and spends $20 a day on gasoline. Write an algebraic expression to represent his earnings for one day. Let x represent the number of hours the electrician works in one day. The electrician's earnings can be represented by the following algebraic expression: 45x - 20

REVIEW

1. FIFTEEN LESS THAN TWICE A NUMBER A x B. 2x + 15 C. 2x - 15 D. None of the above.

1. FIFTEEN LESS THAN TWICE A NUMBER A x B. 2x + 15 C. 2x - 15 D. None of the above.

2. THREE TIMES A NUMBER, INCREASED BY SEVENTEEN A.3(a + 17) B.3a + 17 C.(17 + 3)a D.None of the above.

2. THREE TIMES A NUMBER, INCREASED BY SEVENTEEN A.3(a + 17) B.3a + 17 C.(17 + 3)a D.None of the above.

3. THE PRODUCT OF NINE AND A NUMBER, DECREASED BY SIX A.9(m - 6) B.6(9 - m) C.9m – 6 D.None of the above.

3. THE PRODUCT OF NINE AND A NUMBER, DECREASED BY SIX A.9(m - 6) B.6(9 - m) C.9m – 6 D.None of the above.

4. THIRTY DIVIDED BY SEVEN TIMES A NUMBER A n B.30(7n) C.7n/30 D.None of the above.

4. THIRTY DIVIDED BY SEVEN TIMES A NUMBER A n B.30(7n) C.7n/30 D.None of the above.

5. JENNY EARNS $30 A DAY WORKING PART TIME AT A SUPERMARKET. WRITE AN ALGEBRAIC EXPRESSION TO REPRESENT THE AMOUNT OF MONEY SHE WILL EARN IN D DAYS. A.30d B.30 + d C.30/d D.None of the above

5. JENNY EARNS $30 A DAY WORKING PART TIME AT A SUPERMARKET. WRITE AN ALGEBRAIC EXPRESSION TO REPRESENT THE AMOUNT OF MONEY SHE WILL EARN IN D DAYS. A.30d B.30 + d C.30/d D.None of the above