Question 286256
Let 2^a = 5 and 2^b = 7. Using exponent rules, solve the equation in terms of a and b.
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0.4^x=343
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0.4 = 2/5 = 2/2^a = 2^(1-a)
343 = 7^3 = 2^3b
--> (2^(1-a))^x = 2^3b
x(1-a)) = 3b
x = 3b/(1-a)