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, the
sentence “If 15 is subtracted from three times a certain number, the result
is 27.”can be translated into the following algebraic equation: 3n – 15 = 27 Solve this equation 3n – 15 = 27
3n + 0 = 42 3n = 42 3n/3 = 42/3 Divide each side by 3 n = 14 Now we substitute the solution for 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 the
original 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(3
X 14), the result is 27. If 15 is subtracted from 42, the result is 27. 42 – 15 = 27 We have just solved a first degree equation. ( The source for the problem statement is: “Intermediate Algebra For College Students” by Jerome E. Kaufman |

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