Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. 6.3 Solving Percent Problems with Equations

Martin-Gay, Prealgebra & Introductory Algebra, 3ed 22 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Key Words of means multiplication (∙) is means equals ()() what (or some equivalent) means the unknown number Let x stand for the unknown number.

Martin-Gay, Prealgebra & Introductory Algebra, 3ed 33 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Translating to an Equation Example: Translate to an equation: 60 is what percent of 40? 60 what percentof40 60 = x  40? is

Martin-Gay, Prealgebra & Introductory Algebra, 3ed 44 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Translating to an Equation Example: Translate to an equation: What number is 18% of 66? What number 18%of66? x = 18%  66 is

Martin-Gay, Prealgebra & Introductory Algebra, 3ed 55 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Translating to an Equation Example: Translate to an equation: 25% of 68 is what number? 25% 68%iswhat number? 25%  68%=x?x? of

Martin-Gay, Prealgebra & Introductory Algebra, 3ed 66 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Remember that an equation is simply a mathematical statement that contains an equal sign (  ). 6  18x equal sign Helpful Hint

Martin-Gay, Prealgebra & Introductory Algebra, 3ed 77 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. 20% of 50  10 20%50  10 percentbaseamount Percent Equation percent ∙ base  amount Solving Percent Problems

Martin-Gay, Prealgebra & Introductory Algebra, 3ed 88 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. When solving a percent equation, write the percent as a decimal or fraction. If your unknown in the percent equation is a percent, don’t forget to convert your answer to a percent. Helpful Hint

Martin-Gay, Prealgebra & Introductory Algebra, 3ed 99 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Solving Percent Problems for the Amount Example: What number is 9% of 65? n=9%65 n= n= is 9% of 65. What number is 9% of 65?

Martin-Gay, Prealgebra & Introductory Algebra, 3ed 10 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Solving Percent Problems for the Base Example: 36 is 6% of what number? 36=6%x 36 is 6% of what number 36 = 0.06n 36 is 6% of 600.

Martin-Gay, Prealgebra & Introductory Algebra, 3ed 11 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Solving Percent Problems for the Percent Example: 24 is what percent of 144? 24=x is what percent of 144?

Martin-Gay, Prealgebra & Introductory Algebra, 3ed 12 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Use the following to see if your answers are reasonable. a percent greater than 100% a percent less than 100% a number larger than the original number a number less than the original number   100% of a number  the number Helpful Hint