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Twice a number is 3 times the square of the number less than one. If the number is positive, what is the value of the

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Twice a number is 3 times the square of the number less than one. If the number is positive, what is the value of the

by VJesus12 » Thu Jun 04, 2020 7:11 am

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Twice a number is 3 times the square of the number less than one. If the number is positive, what is the value of the number?

(A) 1

(B) 1/2

(C) 1/3

(D) 2/3

(E) 3/2

[spoiler]OA=C[/spoiler]

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Re: Twice a number is 3 times the square of the number less than one. If the number is positive, what is the value of th

by deloitte247 » Fri Jun 05, 2020 4:19 am
Let the number = x
$$2x=1-\left(3x^2\right)$$
$$2x=1-3x^2$$
$$3x^2+2x-1=0$$
$$3x^2+3x-1x-1=0$$
$$3x\left(x+1\right)-1\left(x+1\right)=0$$
$$3x-1=0\ or\ x+1=0$$
$$x=\frac{1}{3}\ or\ x=-1$$
Given that the number is positive, x cannot be negative
$$so\ x\ne-1$$
$$x\ =\ \frac{1}{3}$$

Answer = C
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Re: Twice a number is 3 times the square of the number less than one. If the number is positive, what is the value of th

by Scott@TargetTestPrep » Tue Jun 09, 2020 4:04 am
VJesus12 wrote: ↑
Thu Jun 04, 2020 7:11 am
 Twice a number is 3 times the square of the number less than one. If the number is positive, what is the value of the number?

(A) 1

(B) 1/2

(C) 1/3

(D) 2/3

(E) 3/2

[spoiler]OA=C[/spoiler]

Solution:

The rather odd wording “3 times the square of the number less than one” actually means to subtract 3 times the square of the number from one. Thus, we can create the equation:

2n = 1 - 3n^2

3n^2 + 2n - 1 = 0

(3n - 1)(n + 1) = 0

n = -1 or n = 1/3

Since n is positive, n = 1/3.

Answer: C

Scott Woodbury-Stewart
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