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(2a^2 b – 3c^3)(3a^3 b + 4c) =
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14 Jan 2022, 03:02
14 Jan 2022, 03:02
Expert Reply
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Question Stats:
77% (01:13) correct
22% (01:14) wrong based on 18 sessions
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\((2a^2 b – 3c^3)(3a^3 b + 4c) =\)
A. \(5a^6b^2 + 12c^4 – 9a^3bc^3 – 12c^4\)
B. \(5a^5b^2 + 8a^2bc – 9a^3bc^3 + 12c^4\)
C. \(6a^5b^2 + 8a^2bc – 9a^3bc^3 + 12c^4\)
D. \(6a^6b^2 + 8a^2bc – 9a^3bc^3 – 12c^4\)
E. \(6a^5b^2 + 8a^2bc – 9a^3bc^3 – 12c^4\)
A. \(5a^6b^2 + 12c^4 – 9a^3bc^3 – 12c^4\)
B. \(5a^5b^2 + 8a^2bc – 9a^3bc^3 + 12c^4\)
C. \(6a^5b^2 + 8a^2bc – 9a^3bc^3 + 12c^4\)
D. \(6a^6b^2 + 8a^2bc – 9a^3bc^3 – 12c^4\)
E. \(6a^5b^2 + 8a^2bc – 9a^3bc^3 – 12c^4\)
Re: (2a^2 b – 3c^3)(3a^3 b + 4c) =
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14 Jan 2022, 03:32
14 Jan 2022, 03:32
The trick I would use here is,
Calculating the first term
2a^2 b * 3a^3 b = 6a^5 b^2
This leaves us with option
C and E only
The term different in those two options isc^4 term
Calculating that out,
We get it as
12c^4 has a - sign.
So the correct answer is E
Calculating the first term
2a^2 b * 3a^3 b = 6a^5 b^2
This leaves us with option
C and E only
The term different in those two options isc^4 term
Calculating that out,
We get it as
12c^4 has a - sign.
So the correct answer is E
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Re: (2a^2 b – 3c^3)(3a^3 b + 4c) =
[#permalink]
14 Jan 2022, 08:02
14 Jan 2022, 08:02
1
Carcass wrote:
\((2a^2 b – 3c^3)(3a^3 b + 4c) =\)
A. \(5a^6b^2 + 12c^4 – 9a^3bc^3 – 12c^4\)
B. \(5a^5b^2 + 8a^2bc – 9a^3bc^3 + 12c^4\)
C. \(6a^5b^2 + 8a^2bc – 9a^3bc^3 + 12c^4\)
D. \(6a^6b^2 + 8a^2bc – 9a^3bc^3 – 12c^4\)
E. \(6a^5b^2 + 8a^2bc – 9a^3bc^3 – 12c^4\)
A. \(5a^6b^2 + 12c^4 – 9a^3bc^3 – 12c^4\)
B. \(5a^5b^2 + 8a^2bc – 9a^3bc^3 + 12c^4\)
C. \(6a^5b^2 + 8a^2bc – 9a^3bc^3 + 12c^4\)
D. \(6a^6b^2 + 8a^2bc – 9a^3bc^3 – 12c^4\)
E. \(6a^5b^2 + 8a^2bc – 9a^3bc^3 – 12c^4\)
We could apply the FOIL method and completely expand and simplify the product.
However we can save a bit of time if we recognize that the first term in the product will be the product of \(2a^2b\) and \(3a^3b\), which is \(6a^5 b^2\)
At this point, we can eliminate answer choices A, B and D since they don't feature \(6a^5 b^2\)
Next we can focus on the last term in the product which will be the product of \(– 3c^3 \)and + \(4c\), which is \(-12c^4\)
This means we can eliminate answer choice C, leaving us with E, the correct answer.
Answer: E
