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Exponential Equation

Question 5
f(x) = 2x + 3 is a function. If f(x) = 10, find x = ?
Solution
Given f(x) = 10, then 2x + 3 = 10 => 2x = 7
Take log to both sides
log2x = log 7 => x log2 = log 7
x = log 7/log 2 = 0.8451/0.3010 = 2.8076
Formula used:
logabx = x logab