SOLUTION: Find the value of x if the arithmetic mean of 3 and 3x + 5 is 8

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Question 978150: Find the value of x if the arithmetic mean of 3 and 3x + 5 is 8
Answer by rothauserc(4718) About Me  (Show Source):
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(3 + 3x + 5) /2 = 8
multiply both sides of = by 2
3x + 8 = 16
subtract 8 from both sides of =
3x = 8
x = 8/3 = 2.6666666 approx 2.7
check answer
(3 + 3*8/3 +5) / 2 = 8
16 /2 = 8
8 = 8
our answer checks