Question 5 • Mathematics III
For the composition, substitute g(x) = 5x − 4 into f(x) = (x − 3)/x. The denominator of f(g(x)) is therefore 5x − 4, which must not equal zero. Solving 5x − 4 = 0 gives x = 4/5, so the domain excludes 4/5; the correct choice is “x such that x is not equal to 4/5.”
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