Answer: 12
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Step-by-step explanation:
First lets compute the value of g(1.5)
Plug x = 1.5 into the g(x) function
g(x) = 8 - 3x
g(1.5) = 8 - 3*1.5 <<--- note how every x is replaced with 1.5
g(1.5) = 8 - 4.5
g(1.5) = 3.5
We ultimately want the value of h(g(1.5)), but that is the same as h(3.5) because we found g(1.5) = 3.5; effectively, g(1.5) and 3.5 are the same value.
Let's compute h(3.5) by plugging in x = 3.5 into the h(x) function.
h(x) = 2x + 5
h(3.5) = 2(3.5) + 5
h(3.5) = 7+5
h(3.5) = 12
h(g(1.5)) = 12 which is the final answer
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An alternative track is to first figure out what h(g(x)) would be in general, by first doing this
h(x) = 2x + 5
h(g(x)) = 2*( g(x) ) + 5 <<---- every x replaced with g(x)
h(g(x)) = 2*( 8-3x ) + 5 <<---- the g(x) replaced with 8-3x
h(g(x)) = 16 - 6x + 5
h(g(x)) = -6x + 21
From here, we plug in x = 1.5
h(g(x)) = -6x + 21
h(g(1.5)) = -6*1.5 + 21
h(g(1.5)) = -9 + 21
h(g(1.5)) = 12 which is the same answer as before