college algebra
posted by brianna .
Let g(x) = 0.5x + 18. Write the rule for g1(x). Then, evaluate g1(x) at x = 20. Enter this result in the space provided.

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Let y = g(x) = 0.5x + 18
0.5x = (y18)
x = 2y 36.
Switch x and y for the inverse function, and x becomes the inverse function g^1(x)
g^1(x) = 2x  36
g^1(20) = 4