If 15 is subtracted from three times a certain number,the result is 27. Find the number. ( If we let n represent the number to be found, thesentence If 15 is subtracted from three times a certain number, the resultis 27.can be translated into the following algebraic equation: 3n15 = 27 Solve this equation 3n15 = 27
3n + 0 =42 3n = 42 3n/3 = 42/3 Divideeach side by 3 n = 14 Now we substitute the solutionfor n into the original equation to see if it works. 3n 15 =27 3(14) 15 = 27 42 15 =27 27= 27 We must also see if the solution works in theoriginal problem statement. If 15 is subtracted from three times a certain number,the result is 27. If 15 is subtracted from three times a certain number(3X 14), the result is 27. If 15 is subtracted from 42, the result is 27. 4215 = 27 We have just solved a first degree equation. ( The source for the problem statement is: Intermediate AlgebraFor College Students by Jerome E. Kaufman |

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