Grade 8 maths · G.4 · Functions
Find the input for a given output
Set the function equal to the output and solve for x.
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f(x) = x + 1. For what value of x is f(x) = 2?
Answer: 1
f(x) = 8x + 2. For what value of x is f(x) = −22?
Answer: -3
f(x) = −3x − 9. For what value of x is f(x) = 3?
Answer: -4
Tip: Set the function equal to the output and solve for x.
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