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Let f(x)=2x squared - 3x+8 what is the value of f(-4)

User Allyson
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1 Answer

14 votes
14 votes

Answer:

f(x) = 52

Explanation:

f(x) does the same things as y, so when you get your answer, think of it as the value for y when x = - 4

The second thing you should know is that wherever you see an x on the right, you put in - 4

Let x = - 4

y = 2x^2 - 3x + 8

y = 2(-4)^2 - 3(-4) + 8

y = 2*16 - (-12) + 8

y = 32 + 12 + 8

y = 52

Be careful how you hand - 3x when -4 is put in for x. -3(-4) = 12 not - 12

f(-4) = 52

User Homan
by
3.3k points
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