Writing Algebraic Expressions Objective Be able to write
Writing Algebraic Expressions Objective: Be able to write an algebraic expression for a word phrase or write a word phrase for an expression.
Warm Up Evaluate each algebraic expression for the given value of the variables. 1. ) 7 x + 4 for x = 6 2. ) 8 y – 22 for y = 9 3. ) 12 x 8 + y 4. ) y + 3 z for y = 5 and z = 6 46 50 for x = 7 and y = 4 86 23
Although they are closely related, a Great Dane weighs about 40 times as much as a Chihuahua. An expression for the weight of the Great Dane could be 40 c, where c is the weight of the Chihuahua. When solving real-world problems, you will need to translate words, or verbal expressions, into algebraic expressions.
Notes In order to translate a word phrase into an algebraic expression, we must first know some key word phrases for the basic operations.
On the back of your notes: Addition Subtraction Multiplication Division
Addition Phrases: More than Increase by Greater than Add Total Plus Sum
Subtraction Phrases: Decreased by Difference between Take Away Less Subtract Less than* Subtract from*
Multiplication Phrases: Product Times Multiply Of Twice or double Triple
Division Phrases: Quotient Divided by Split equally
Notes Multiplication expressions should be written in side-by-side form, with the number always in front of the variable. 3 a 2 t 1. 5 c 0. 4 f
Notes Division expressions should be written using the fraction bar instead of the traditional division sign.
Examples Addition phrases: n 3 more than x n the sum of 10 and a number c n a number n increased by 4. 5
Examples Subtraction phrases: n a number t decreased by 4 n n the difference between 10 and a number y 6 less than a number z
Examples Multiplication phrases: n the product of 3 and a number t n twice the number x n 4. 2 times a number e
Examples Division phrases: n the quotient of 25 and a number b n the number y divided by 2 n 2. 5 divide g
Examples converting f feet into inches a car travels at 75 mph for h hours the area of a rectangle with a length of 10 and a width of w
Examples converting i inches into feet the cost for tickets if you purchase 5 adult tickets at x dollars each the cost for tickets if you purchase 3 children’s tickets at y dollars each
Examples the total cost for 5 adult tickets and 3 children’s tickets using the dollar amounts from the previous two problems (problems e and f)
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