SOLUTION: The general expression for consecutive multiples of seven 7n, 7(n+1), 7(n+2)where n is some unspecified integer. Find three consecutive multiples of seven such that the product of

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Question 1132517: The general expression for consecutive multiples of seven 7n, 7(n+1), 7(n+2)where n is some unspecified integer. Find three consecutive multiples of seven such that the product of -3 and the sum of the first and third is 21 less than five times opposite of a second.
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
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The general expression for consecutive multiples of seven 7n, 7(n+1), 7(n+2)where n is some unspecified integer.
Find three consecutive multiples of seven such that the product of -3 and the sum of the first and third is 21 less than five times opposite of a second.
:
-3(7n+7(n+2)) = -5(7(n+1)) - 21
-3(7n + 7n + 14) = -5(7n + 7) -21
-3(14n + 14) = -35n - 35 - 21
-42n - 42 = -35n - 56
multiply by -1
42n + 42 = 35n + 56
42n - 35n = 56 -42
7n = 14
n = 2
The three consecutive multiples of 7: 7(2), 7(3), 7(4) or
14, 21, 28
:
:
See if that works
-3((14) + (28)) = 5(-21) - 21
-3(42) = -105 - 21
-26 = -26