Answer: -29
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Work Shown:
f(x) = 6x + b
f(5) = 6(5) + b .... replace every x with 5
f(5) = 30 + b
1 = 30 + b ..... replace f(5) with 1, since f(5) = 1 was given.
1-30 = 30 + b - 30 .... subtract 30 from both sides
-29 = b
b = -29
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The function f(x) = 6x+b turns into f(x) = 6x+(-29) which is equivalent to f(x) = 6x-29
Plugging in x = 5 leads to
f(x) = 6x-29
f(5) = 6(5) - 29
f(5) = 30 - 29
f(5) = 1
So we have confirmed the answer.