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20 votes
20 votes
Given f(x) = x^2- 3x + 5, what is f(-2)?

User Alex Davies
by
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2 Answers

14 votes
14 votes

Explanation:

f(x) = x² - 3x + 5

f(-2) = (-2)² - 3.(-2) + 5

f(-2) = 4 + 6 + 5

f(-2) = 15

User Jim Leask
by
3.2k points
13 votes
13 votes

Answer:

Explanation:

Comment

In general, f(x) can be thought of as being y. So the equation could read as "Let x = - 2" when y = x^2 - 3x + 5.

Another way of thinking of it is by saying f(-2), wherever you see an x on the right hand side, substitute the value given on the left side (in this case x = - 2

Solution

f(-2) = (-2)^2 - 3x + 5

f(-2) = 4 - 3(-2) + 5 Combine

f(-2) = 4 + 6 + 5 Add

f(-2) = 15

User Kazbeel
by
3.1k points