SOLUTION: 3^(x+3)+3^x=84 (hint 3^x+3=3^x3^3) please help... Solve the equation

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Question 323018: 3^(x+3)+3^x=84 (hint 3^x+3=3^x3^3) please help... Solve the equation
Found 2 solutions by Fombitz, jessica43:
Answer by Fombitz(32388)   (Show Source): You can put this solution on YOUR website!




Answer by jessica43(140)   (Show Source): You can put this solution on YOUR website!
The first step is to use the hint you were given (hint 3^(x+3)=(3^x)*(3^3)) to rewrite the problem:
(3^(x+3))+(3^x) = 84
((3^x)*(3^3))+(3^x) = 84
Now you can factor out the (3^x) and solve:
((3^x)*(3^3))+(3^x) = 84
(3^x)*((3^3)+1) = 84
(3^x)*(27+1) = 84
(3^x)*28 = 84
(3^x)= 3
x= 1
So your answer is x=1.

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