Find \( f(g(x)) \) and \( g(f(x)) \) and determine whether the pair of functions \( f \) and \( g \) are inverses of each \( f(x)=9 x-7 \) and \( g(x)=\frac{x+9}{7} \) a. \( f(g(x))=\square \) (Simplify your answer. Use integers or fractions for any numbers in the expression.)
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To find \( f(g(x)) \), we start by substituting \( g(x) \) into \( f(x) \). Given: \[ f(x) = 9x - 7 \] \[ g(x) = \frac{x + 9}{7} \] Now, substituting \( g(x) \) into \( f(x) \): \[ f(g(x)) = f\left(\frac{x + 9}{7}\right) = 9\left(\frac{x + 9}{7}\right) - 7 \] Calculating: \[ = \frac{9(x + 9)}{7} - 7 = \frac{9x + 81}{7} - 7 \] To combine the terms, we need a common denominator: \[ = \frac{9x + 81}{7} - \frac{49}{7} = \frac{9x + 81 - 49}{7} = \frac{9x + 32}{7} \] Thus: \[ f(g(x)) = \frac{9x + 32}{7} \] Next, we will find \( g(f(x)) \): Substituting \( f(x) \) into \( g(x) \): \[ g(f(x)) = g(9x - 7) = \frac{(9x - 7) + 9}{7} = \frac{9x + 2}{7} \] So, our results are: \[ f(g(x)) = \frac{9x + 32}{7} \] \[ g(f(x)) = \frac{9x + 2}{7} \] To determine if \( f \) and \( g \) are inverses of each other, we check if \( f(g(x)) = x \) and \( g(f(x)) = x \). 1. For \( f(g(x)) = \frac{9x + 32}{7} \): This does not equal \( x \). 2. For \( g(f(x)) = \frac{9x + 2}{7} \): This also does not equal \( x \). Therefore, \( f \) and \( g \) are not inverses of each other. Final answer: a. \( f(g(x)) = \frac{9x + 32}{7} \)