SOLUTION: Find the value of x and y if 7^x+y=343 and 7^x-y=49?

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Question 1042626: Find the value of x and y if 7^x+y=343 and 7^x-y=49?
Found 2 solutions by ikleyn, stanbon:
Answer by ikleyn(52834)   (Show Source): You can put this solution on YOUR website!
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Find the value of x and y if 7^x+y=343 and 7^x-y=49?
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Are you a novice in this site?

Your writing is ambiguous. To avoid ambiguity, use parentheses.
It is mandate when you post formulas to this site.


So , I am reading your post in this way:  = 343,   = 49.


Then 

x + y = 3, 
x - y = 2,

and you can easily solve it on your own, if you add the two equations as the first step.


Answer by stanbon(75887)   (Show Source): You can put this solution on YOUR website!
Find the value of x and y if 7^x+y=343 and 7^x-y=49?
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Note: 343 = 7^3
49 = 7^2
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7^(x+y) = 7^3
7^(x-y) = 7^2
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x+y = 3
x-y = 2
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Add and solve for "x"::
2x = 5
x = 5/2
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y = x - 2 = (5/2)-2 = 1/2
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Cheers,
Stan H.
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