<PRE><B>Question 549870</B>
How do I make the equation y=ab^x with two points, (5,4) and (7,9)? 
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4 = a*b^5
9 = a*b^7
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log(4) = log(a) + 5log(b)
log(9) = log(a) + 7log(b)
--------------------------- Subtract
log(4/9) = -2log(b) = 1/log(b^2)
b^2 = 9/4
b = 3/2
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4 = a*b^5 = a*(3/2)^5
a = 4*(2/3)^5
a = 128/243
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y = (128/243)*(3/2)^x
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