Math 1-7: Warm-up Multiply. 3(-4) -6(-2) Divide 66 ÷ (-11) Find the mean of the set of integers. 5. 3, -6, -8, -10, -4 What is the value of ab – c, if a = -3, b = 4, and c = -2? A. -14 B. -10 C. 10 D. 12

Math 1-7: Writing Expressions and Equations Objective: How to write algebraic expressions and equations from verbal phrases and sentences.

Vocabulary defining a variable – choosing a variable and an unknown quantity for the variable to represent Review: expression – contains numbers, at least one operation, and possibly variables equation – mathematical sentence that contains an equal sign (=)

Common words/phrases Addition or Subtraction Multiplication or Division plus increased by minus subtract times each divided rate sum in all less decreased by product of quotient ratio total more than less than difference multiplied factors an, in, or per separate

More than one phrase… x + 8 r – 6 4n n – 9 = 45 Phrases Expression 8 more than a number the sum of 8 and a number x plus 8 x increased by 8 x + 8 the difference of r and 6 6 subtracted from a number 6 less than a number r minus 6 r – 6 4 multiplied by n 4 times a number the product of 4 and n 4n a number divided by 3 the quotient of z and 3 the ratio of z and 3 Sentences Equation 9 less than a number is equal to 45 the difference of a number and 9 is 45 a number decreased by 9 is 45 45 is equal to a number minus 9 n – 9 = 45

Examples Write each verbal phrase as an algebraic expression. the sum of 8 and t 8 + t the quotient of g and 15 the product of 5 and b 5b p increased by 10 p + 10

double the price of a loaf of bread 14 less than f f – 14 the difference of 32 and x 32 – x double the price of a loaf of bread 2p stalks of celery are divided into 4 portions

Examples Write each verbal phrase as an algebraic equation. 5 more than a number is 6 n + 5 = 6 the product of 7 and b is equal to 63 7b = 63 the sum of r and 45 is 79 r + 45 = 79 the quotient of x and 7 is equal to 13

the original price decreased by $5 is $34 x – 5 = 34 the price of the book plus $5 shipping is $29 b + 5 = 29 30 is 6 times a number 30 = 6n 5 shirts at $d each is $105.65 5d = 105.65

Assignment 1-7 Practice Skills (1-10a; 15-24a) 1-7 Enrichment (ec)