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What is the value of x^2yz − xyz^2, if x = − 2, y = 1, and z = 3?

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What is the value of x^2yz − xyz^2, if x = − 2, y = 1, and z = 3?  [#permalink]

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New post 10 Jan 2016, 07:27
00:00
A
B
C
D
E

Difficulty:

  5% (low)

Question Stats:

95% (00:48) correct 5% (01:27) wrong based on 518 sessions

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Re: What is the value of x^2yz − xyz^2, if x = − 2, y = 1, and z = 3?  [#permalink]

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New post 11 Jan 2016, 06:54
Given : x = − 2, y = 1, and z = 3

x^2yz − xyz^2,
= xyz (x- z)
= (-2)(1)(3) [ (-2) - 3]
= (-6)*(-5)
= 30
Hence C.
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Re: What is the value of x^2yz − xyz^2, if x = − 2, y = 1, and z = 3?  [#permalink]

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New post 11 Jan 2016, 19:43
4*1*3 -(- 2*1*9)
=12+18 = 30

Ans: C
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Re: What is the value of x^2yz − xyz^2, if x = − 2, y = 1, and z = 3?  [#permalink]

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New post 21 May 2016, 07:41
can someone please explain this a bit more? I just substituted and definitely didnt come close
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Re: What is the value of x^2yz − xyz^2, if x = − 2, y = 1, and z = 3?  [#permalink]

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New post 21 May 2016, 07:45
2
JSS16 wrote:
can someone please explain this a bit more? I just substituted and definitely didnt come close



Hi,

the Q is --- What is the value of x^2yz − xyz^2, if x = − 2, y = 1, and z = 3? ..

\(x^2yz − xyz^2 = xyz(x-z) = (-2)*1*3*(-2-3) = (-2)*1*3*(-5) = 1*3*10=30\)...
C
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Re: What is the value of x^2yz − xyz^2, if x = − 2, y = 1, and z = 3?  [#permalink]

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New post 21 May 2016, 10:58
1
Bunuel wrote:
What is the value of x^2yz − xyz^2, if x = − 2, y = 1, and z = 3?

(A) 20
(B) 24
(C) 30
(D) 32
(E) 48



\(x^2\)\(yz\) = \(-2^2\)\((1*3)\) => 12

\(xy\)\(z^2\) = \((-2*1)3^2\) => -18

So, \(x^2\)\(yz\) − \(xy\)\(z^2\) = 12 - (-18) => 30

Hence answer will be (C) 30
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Re: What is the value of x^2yz − xyz^2, if x = − 2, y = 1, and z = 3?  [#permalink]

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New post 11 Oct 2016, 23:33
Bunuel wrote:
What is the value of x^2yz − xyz^2, if x = − 2, y = 1, and z = 3?

(A) 20
(B) 24
(C) 30
(D) 32
(E) 48



The confusion created in this question is that they could have included brackets.

ie (x^2)yz - xyz^2..

Else people like me will take x^(2yz)-xyz^2.

Is there any rule for this? Please tell me if so.
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Re: What is the value of x^2yz − xyz^2, if x = − 2, y = 1, and z = 3?  [#permalink]

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New post 12 Oct 2016, 00:02
1
wolf020287 wrote:
Bunuel wrote:
What is the value of x^2yz − xyz^2, if x = − 2, y = 1, and z = 3?

(A) 20
(B) 24
(C) 30
(D) 32
(E) 48



The confusion created in this question is that they could have included brackets.

ie (x^2)yz - xyz^2..

Else people like me will take x^(2yz)-xyz^2.

Is there any rule for this? Please tell me if so.


x^2yz mathematically can only mean x^2*y*z. If it were 2 to the power of 2yz, then it would be written as x^(2yz). Still edited the original post to avoid confusion.
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Re: What is the value of x^2yz − xyz^2, if x = − 2, y = 1, and z = 3?  [#permalink]

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New post 12 Oct 2016, 02:03
Bunuel wrote:
What is the value of \(x^2yz − xyz^2\), if x = − 2, y = 1, and z = 3?

(A) 20
(B) 24
(C) 30
(D) 32
(E) 48


\((-2)^2*1*3 − (-2)*1*3^2\)

=4*1*3 - ( -2)*1*9
= 12 - (-18)
= 30

Hence answer will be (C) 30

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What is the value of x^2yz − xyz^2, if x = − 2, y = 1, and z = 3?  [#permalink]

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New post 11 Apr 2017, 22:59
For this question, you must to remember that you need to factor common terms out, then it's just plug and play, and obviously, avoid silly mistakes (I'm talking directly to myself here!) and go bit by bit, just like Jack the Ripper:

\({ x }^{ 2 }yz-xy{ z }^{ 2 }=\\ xyz\left( x-y \right) =\\ \left[ \left( -2 \right) \left( 1 \right) \left( 3 \right) \right] \left( -2-3 \right) =\\ \left( -6 \right) \left( -5 \right) =\\ 30\)
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Re: What is the value of x^2yz − xyz^2, if x = − 2, y = 1, and z = 3?  [#permalink]

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New post 06 Sep 2018, 08:28
xyz(x-z)
(-2)(1)(3)(-2-3)
(-6)(-5)
30
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Re: What is the value of x^2yz − xyz^2, if x = − 2, y = 1, and z = 3? &nbs [#permalink] 06 Sep 2018, 08:28
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