SOLUTION: write an exponential equation whose graph passes through the given points (1,5) (2,7)

Algebra ->  Exponential-and-logarithmic-functions -> SOLUTION: write an exponential equation whose graph passes through the given points (1,5) (2,7)      Log On


   

Question 612902: write an exponential equation whose graph passes through the given points
(1,5) (2,7)
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
y+=+a%2Ab%5Ex

5+=+a%2Ab%5E%281%29

5%2F%28b%29+=+a

a+=+5%2F%28b%29


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y+=+a%2Ab%5Ex

7+=+%285%2F%28b%29%29%2Ab%5E%282%29

7+=+5b%5E%282+-+1%29

7+=+5b

7%2F5+=+b

b+=+7%2F5


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y+=+a%2Ab%5Ex

y+=+a%2A%287%2F5%29%5Ex

5+=+a%2A%287%2F5%29%5E%281%29

5+=+a%287%2F5%29

5%2A5+=+7a

25+=+7a

25%2F7+=+a

a+=+25%2F7


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y+=+a%2Ab%5Ex

y+=+%2825%2F7%29%2A%287%2F5%29%5Ex


So the exponential equation in the form y=ab%5Ex that passes through (1,5) and (2,7) is y+=+%2825%2F7%29%2A%287%2F5%29%5Ex