A student is solving the following problem: Cody is 44 years younger than Kathryn. 7 years ago, Kathryn's age was 3 times Cody's age. How old is Kathryn now? The student writes out his solution, noting what he did: Cody now = c, so Cody 7 years ago was c -7 Kathryn now = k, so Kathryn 7 years ago was k -7 Cody is 44 years younger than Kathryn, so c = 44 - k 7 years ago, Kathryn's age was 3 times Cody's age k-7 = 3(c - 7) k-7 = 3[44 - k - 7] Substitute for c using c = 44 - k k-7 = 3[-k + 37] Simplify k-7 = -3k + 111 4k = 118 k = 29.5 There is no way that Kathryn's age is 29.5 if Cody is supposed to be 44 years younger than Kathryn, so what went wrong? What mistake did the student make?

A student is solving the following problem: Cody is 44 years younger than Kathryn. 7 years ago, Kathryn's age was 3 times Cody's age. How old is Kathryn now? The student writes out his solution, noting what he did: Cody now = c, so Cody 7 years ago was c -7 Kathryn now = k, so Kathryn 7 years ago was k -7 Cody is 44 years younger than Kathryn, so c = 44 - k 7 years ago, Kathryn's age was 3 times Cody's age k-7 = 3(c - 7) k-7 = 3[44 - k - 7] Substitute for c using c = 44 - k k-7 = 3[-k + 37] Simplify k-7 = -3k + 111 4k = 118 k = 29.5 There is no way that Kathryn's age is 29.5 if Cody is supposed to be 44 years younger than Kathryn, so what went wrong? What mistake did the student make?

Algebra and Trigonometry (6th Edition)

6th Edition

ISBN:9780134463216

Author:Robert F. Blitzer

Publisher:Robert F. Blitzer

ChapterP: Prerequisites: Fundamental Concepts Of Algebra

Section: Chapter Questions

Problem 1MCCP: In Exercises 1-25, simplify the given expression or perform the indicated operation (and simplify,...

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