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Example 1:

If f(x) = 3x-4, find each value. Show all work.

a) ƒ(4)

b) f(-5)

c) f(2-x)

User Mpowered
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1 Answer

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Answer: f(4) = 8, f(-5) = -19, f(2-x) = -3x+2

Explanation:

Let's start by analyzing what we are given:

f(x)=3x-4

In this equation, f is the name of the function.

The number in the parentheses represents x.

The 3x-4 tells us what the equation does. In this instance, we multiply x by 3 and then subtract 4.

Let's start with (a).

f(4)

Since we have established that the number in the parentheses is x, we can plug 4 in for x into the equation f. We must abide by the order of operations. Therefore, we can obtain the following:

f(4) = 3(4) -4

f(4) = 12 -4

f(4) = 8

We can continue this for part (b).

f(-5) = 3(-5) -4

f(-5) = -15-4

f(-5) = -19

Part (c) is slightly different, but applies the same principles we established previously. On this part, we must recall the distributive property. The 3 multiples the 2 and the x. We must also remember to combine like terms.

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

f(2-x) = 6 - 3x -4

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

User Jtolle
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