If 27 is subtracted from three times a certain number,
the result is 18. Find the number. ( If we let n represent the number to be found, the
sentence “If 27 is subtracted from three times a certain number, the result
is 18.”can be translated into the following algebraic equation: 3n – 27 = 18 Solve this equation 3n – 27 = 18
3n + 0 = 45 3n = 45 3n/3 = 45/3 Divide each side by 3 n = 15 Now we substitute the solution for n into the original equation to see if it works. 3n – 27 =
18 3(15) – 27 = 18 45 – 27 =
18 18
= 18 We must also see if the solution works in the
original problem statement. If 27 is subtracted from three times a certain number,
the result is 18. If 27 is subtracted from three times a certain number(3
X 15), the result is 18. If 27 is subtracted from 45, the result is 18. 45 – 27 = 18 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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