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For what integer value of x is f(x) = -10 if f(x) = - 4x + 2?​

User Thomas Vervest
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1 Answer

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17 votes

Answer:

x = 3

Explanation:

Given the linear function, f(x) = -4x + 2, for which we must determine the integer value of x that will provide an output of f(x) = -10:

Solution:

The first step is to substitute the output value, f(x) = -10, into the given function, and solve for its corresponding input value, x:

f(x) = -4x + 2

-10 = -4x + 2

Subtract 2 from both sides:

-10 - 2 = -4x + 2 - 2

-12 = -4x

Divide both sides by -4 to solve for x:


\displaystyle\mathsf{(-12)/(-4)\:=\:(-4x)/(-4) }

x = 3

Hence, when x = 3, f(x) = -10.

Double-check:

Substitute the value of x = 3 into the original function:

f(x) = -4x + 2

f(3) = -4(3) + 2

f(3) = -12 + 2

f(3) = -10 ⇒ f(x) = -10.

Therefore, the input value of x = 3 gives an output value of f(x) = -10.

User Enchantner
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