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Joined: 19 Nov 2020
Posts: 326
Given Kudos: 64
GRE 1: Q160 V152
What is the sum of the roots of the equation ...
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29 Jul 2021, 17:23
29 Jul 2021, 17:23
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Question Stats:
55% (01:08) correct
44% (01:57) wrong based on 18 sessions
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What is the sum of the roots of the equation \(5x^2-x=39\) ?
(A) 0
(B) 0.2
(C) 0.5
(D) 0.7
(E) 1
(A) 0
(B) 0.2
(C) 0.5
(D) 0.7
(E) 1
Re: What is the sum of the roots of the equation ...
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29 Jul 2021, 18:23
29 Jul 2021, 18:23
This requires the quadratic formula.
We know it is (-b ± sqrt(b^2 - 4ac)) / 2a, which splits into...
(-b + sqrt(b^2 - 4ac)) / 2a
(-b - sqrt(b^2 - 4ac)) / 2a
AKA the 2 roots!!!
Adding these up we get -2b / 2a.
Here we know b = -1 and a = 5 after we get the formula in the form 5x^2 - x - 39 = 0 (ax^2 + bx + c = 0).
No we plug and chug and we get 1/5 which is .2.
The answer is B! I hope this helps.
We know it is (-b ± sqrt(b^2 - 4ac)) / 2a, which splits into...
(-b + sqrt(b^2 - 4ac)) / 2a
(-b - sqrt(b^2 - 4ac)) / 2a
AKA the 2 roots!!!
Adding these up we get -2b / 2a.
Here we know b = -1 and a = 5 after we get the formula in the form 5x^2 - x - 39 = 0 (ax^2 + bx + c = 0).
No we plug and chug and we get 1/5 which is .2.
The answer is B! I hope this helps.
What is the sum of the roots of the equation ...
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05 Feb 2022, 00:26
05 Feb 2022, 00:26
Sum of the roots of a quadratic equation = -b/a
a = 5
b = -1
(-(-1))/5 = 1/5 = 0.2
Answer B
a = 5
b = -1
(-(-1))/5 = 1/5 = 0.2
Answer B
