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If the product of
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22 Jul 2019, 02:45
22 Jul 2019, 02:45
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74% (01:15) correct
24% (01:24) wrong based on 112 sessions
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If the product of \(\frac{ab}{c}\) and \(\frac{b}{cd}\) is negative, which two of the following variables must have a product that is less than zero?
Indicate two such variables.
A. a
B. b
C. c
D. d
Indicate two such variables.
A. a
B. b
C. c
D. d
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Re: If the product of
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24 Jul 2019, 10:42
24 Jul 2019, 10:42
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Carcass wrote:
If the product of \(\frac{ab}{c}\) and \(\frac{b}{cd}\) is negative, which two of the following variables must have a product that is less than zero?
Indicate two such variables.
A. a
B. b
C. c
D. d
Indicate two such variables.
A. a
B. b
C. c
D. d
GIVEN: (ab/c)(b/cd) = some negative number
Simplify to get: (ab²)/(c²d) = some negative number
Rewrite to get: (a/d)(b²/c²) = some negative number
Notice that b²/c² must be POSITIVE
So, we can write: (a/d)(POSITIVE) = some NEGATIVE number
Divide both sides by (POSITIVE) to get: a/d = (some NEGATIVE number)/(some POSITIVE number)
Simplify to get: a/d = NEGATIVE
This means one value (a or d) must be POSITIVE and the other must be NEGATIVE
As such, we can be certain that ad is NEGATIVE
Answer: A & D
If the product of
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16 Jan 2024, 05:42
16 Jan 2024, 05:42
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\(\dfrac{ab}{c} \times \dfrac{b}{cd} = \dfrac{ab^2}{c^2d}\)
\(\dfrac{ab^2}{c^2d}<0\)
Since \(b^2\) and \(c^2\) are positive either \(a\) or \(d\) must be negative. Or the product of \(a\) and \(d\) must be negative.
The answer is A and D.
\(\dfrac{ab^2}{c^2d}<0\)
Since \(b^2\) and \(c^2\) are positive either \(a\) or \(d\) must be negative. Or the product of \(a\) and \(d\) must be negative.
The answer is A and D.
