Question 745105
f(x)=4-5x and g(x)=4/5-1/5 x are inverse functions
Carefully show that (fog)(x)=x and show that (gof)(x)=x.

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f(x) = 4-5x ; g(x) = (4-x)/5
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fog(x) = f[g(x)] = f[(4-x)/5]
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= 4-5[(4-x)/5]
= 4-(4-x)
= x
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gof(x) = g[f(x)] = g[(4-5x)] = (4-[(4-5x))/5
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= (5x)/5
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= x 
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Cheers,
Stan H.
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