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Consider the function f(x) = x 2 – 5x. For which value(s) of
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20 Jul 2019, 02:50

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Question Stats:

Consider the function \(f(x) = x^2 – 5x\). For which value(s) of x does \(f(x) = 14\)?

Indicate all that apply.

A. 19

B. 14

C. 7

D. 2

E. 0

F. –2

G. –7

Indicate all that apply.

A. 19

B. 14

C. 7

D. 2

E. 0

F. –2

G. –7

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Re: Consider the function f(x) = x 2 – 5x. For which value(s) of
[#permalink]
20 Jul 2019, 05:16

Carcass wrote:

Consider the function \(f(x) = x^2 – 5x\). For which value(s) of x does \(f(x) = 14\)?

Indicate all that apply.

A. 19

B. 14

C. 7

D. 2

E. 0

F. –2

G. –7

Indicate all that apply.

A. 19

B. 14

C. 7

D. 2

E. 0

F. –2

G. –7

We are looking for values of x so that \(f(x) = 14\)

In other words, we want values of x so that \(x^2 – 5x = 14\)

This is a quadratic equation, so we should first set it equal to zero

Subtract 14 from both sides to get: \(x^2 – 5x - 14 = 0\)

Factor to get: \((x - 7)(x + 2) = 0\)

So, EITHER \((x - 7) = 0\) OR \((x + 2) = 0\)

If \((x - 7) = 0\), then \(x = 7\)

If \((x + 2) = 0\), then \(x = -2\)

Answer: C and F

Cheers,

Brent

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Status:**GRE Quant Tutor**

Posts: **1097**

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WE:**Engineering (Computer Software)**

Re: Consider the function f(x) = x 2 – 5x. For which value(s) of
[#permalink]
06 Jan 2022, 10:47

1

Given that \(f(x) = x^2 – 5x\) and we need to find those values of x for which \(f(x) = 14\)

f(x) = 14

=> \(x^2 – 5x = 14\)

=> \( x^2 - 5x - 14 = 0\)

=> \( x^2 - 7x + 2x - 14 = 0\)

=> x(x-7) +2(x-7) = 0

=> (x-7)*(x+2) = 0

=> x = -2, 7

So, Answer will be C and F

Hope it helps!

Watch the following video to learn the Basics of Functions and Custom Characters

f(x) = 14

=> \(x^2 – 5x = 14\)

=> \( x^2 - 5x - 14 = 0\)

=> \( x^2 - 7x + 2x - 14 = 0\)

=> x(x-7) +2(x-7) = 0

=> (x-7)*(x+2) = 0

=> x = -2, 7

So, Answer will be C and F

Hope it helps!

Watch the following video to learn the Basics of Functions and Custom Characters

Re: Consider the function f(x) = x 2 – 5x. For which value(s) of
[#permalink]
09 Jan 2022, 11:18

Why do you solve this question as a quadratic in this example but not in the subsequent question which is the same format?

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Re: Consider the function f(x) = x 2 – 5x. For which value(s) of
[#permalink]
09 Jan 2022, 13:30

Rdlynch2 wrote:

Why do you solve this question as a quadratic in this example but not in the subsequent question which is the same format?

Who are you directing your question to?

Also, what subsequent question are you referring to?

Re: Consider the function f(x) = x 2 – 5x. For which value(s) of
[#permalink]
09 Jan 2022, 15:31

Im asking to whoever can answer. The other question I have referring to is the other most recent post outside of this one that asks essentially the same question, but doesn't set up as a quadratic

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Re: Consider the function f(x) = x 2 – 5x. For which value(s) of
[#permalink]
10 Jan 2022, 08:55

You can share the link of "the other most recent post outside of this one that asks essentially the same question, but doesn't set up as a quadratic"

for "whoever can answer" to respond.

for "whoever can answer" to respond.

Rdlynch2 wrote:

Im asking to whoever can answer. The other question I have referring to is the other most recent post outside of this one that asks essentially the same question, but doesn't set up as a quadratic

Consider the function f(x) = x 2 5x. For which value(s) of
[#permalink]
16 Jan 2024, 05:29

1

If \(f(x)=x^2-5x\), for which values of \(x\) does \(f(x)=14\)?

Let \(f(x) = 14\)

then, we have,

\(x^2-5x=14\)

\(x^2-5x-14=0\)

\(x^2-7x+2x-14=0\)

\(x(x-7)+2(x-7)=0\)

\((x+2)(x-7)=0\)

\(x=-2 \text{ and } x=7\)

The answers are C and F.

Let \(f(x) = 14\)

then, we have,

\(x^2-5x=14\)

\(x^2-5x-14=0\)

\(x^2-7x+2x-14=0\)

\(x(x-7)+2(x-7)=0\)

\((x+2)(x-7)=0\)

\(x=-2 \text{ and } x=7\)

The answers are C and F.

gmatclubot

Consider the function f(x) = x 2 5x. For which value(s) of [#permalink]

16 Jan 2024, 05:29
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