Open In App

Aptitude | Algebra | Question 7

Last Updated : 12 Oct, 2021
Improve
Improve
Like Article
Like
Save
Share
Report

If x1/3 + y1/3 – z1/3 = 0 then value of (x + y – z)3 + 27xyz is
(A) 8
(B) 2
(C) 0
(D) 6


Answer: (C)

Explanation:

x1/3 + y1/3 = z1/3
Now cubing both sides we get 
x + 3x1/3y1/3(x1/3 + y1/3) + y = z
or, (x + y - z) = -3x1/3y1/3z1/3
Cubing again both sides, (x + y - z) = -27xyz.
So answer is zero


Quiz of this Question


Similar Reads

Aptitude | Algebra | Question 2
The value of x+1/2x is given as 2, then find the value of 8x3+1/x3 (A) 40/3 (B) 20/7 (C) 28 (D) 40 Answer: (D)Explanation: x3 + 1/8x3 + 3.x.1/2x(x + 1/2x) = (x+1/2x)3 x3 + 1/8x3 + 3 = 23 x3 + 1/8x3 = 5 8x3 + 1/x3 = 5.8 = 40 Quiz of this QuestionPlease comment below if you find anything wrong in the above post
1 min read
Aptitude | Algebra | Question 4
For what value of x, the following equation: 5√x +12√x =13√x will be true? (A) -2 (B) 0 (C) 3 (D) None of the above Answer: (D)Explanation: say x=117!=13for, x=2 and 3 also not possible x=4 52+122=132 169=169 Quiz of this QuestionPlease comment below if you find anything wrong in the above post
1 min read
Aptitude | Algebra | Question 5
Solve for x in the equation: log(2x - 1) + log(3) = log(x + 5) (A) x = -1/3 (B) x = 1/3 (C) x = 5/3 (D) x = 8/5 Answer: (D) Explanation: Using the property of logarithms that states log(a) + log(b) = log(ab), we can simplify the equation as log(3(2x - 1)) = log(x + 5). Therefore, we have 6x - 3 = x + 5. Simplifying, we get 5x = 8, which gives us x
1 min read
Aptitude | Algebra | Question 6
If the value of b2 + 1⁄b2 = 1, then find the value of b3 + 1⁄b3 (A) -1/12 (B) -2 (C) -4 (D) None of the above Answer: (D)Explanation:E = (b + 1⁄b)(b2 - 1 + 1⁄b2)Quiz of this QuestionPlease comment below if you find anything wrong in the above post
1 min read
Aptitude | Algebra | Question 8
[caption width="800"] [/caption] (A) 1 + 1/(x+4) (B) x+4 (C) 1/x (D) (x+4)/ x Answer: (D) Explanation:[caption width="800"] [/caption] Quiz of this Question Please comment below if you find anything wrong in the above post
1 min read
Aptitude | Algebra | Question 9
If a+b+c = 0, then the value of (a^2/bc) + (b^2/ac) + (c^2/ab) will be? (A) 3 (B) 2 (C) 1 (D) 0 Answer: (A) Explanation:[caption width="800"] [/caption] Quiz of this Question Please comment below if you find anything wrong in the above post
1 min read
Aptitude | Algebra | Question 1
Given two numbers x and y such that 1. x3 + y3 = 9 2. x + y = 3 Find the value of x4+y4 (A) 2/3 (B) 7 (C) 13 (D) 17 Answer: (D)Explanation:x3+y3 = (x + y) × (x2 − xy + y2) Putting given values of x3+y3 and (x + y) 9 = 3 × ((x+y)2 − 3xy) = 3 × (9 − 3xy) = 27 − 9xy 9xy = 18 xy = 2 x4 + y4 = (x2 + y2)2 - 2x2y2 = (x2 + y2)2 - 2*4 [Putting value of xy]
1 min read
Aptitude | Algebra | Question 3
If x takes only real numbers. For what value of x, the value of the expression: 4−6x−x2 will be maximum? (A) -4 (B) -3 (C) 0 (D) 3 Answer: (B)Explanation: Differentiate and equate to 0 6+2x =0 x=−3 Quiz of this QuestionPlease comment below if you find anything wrong in the above post
1 min read
QA - Placement Quizzes | Algebra | Question 10
4/15 of 5/7 of a number is greater than 4/9 of 2/5 of the same number by 8. What is half of that number? (A) 630 (B) 63 (C) 315 (D) 105 Answer: (C) Explanation: Let the number be x. Then, 4/15 of 5x/7 = 4/9 of 2x/5 + 8 4/15 * 5x/7 = 4/9 * 2x/5 + 8 4x/21 = 8x/45 + 8 x/21 = 2x/45 + 2 x/21 = (2x + 90)/45 45x = 21(2x + 90) 45x = 42x + 90*21 3x = 90*21
1 min read
QA - Placement Quizzes | Algebra | Question 11
If 2x/(1 + 1/(1 + x/(1 - x))) = 1, then find the value of x. (A) 1/3 (B) 2/3 (C) 1/2 (D) 3/2 Answer: (B) Explanation: We have 2x/(1 + 1/(1 + x/(1-x))) = 1 2x/(1 + 1/((1-x+x)/(1-x))) = 1 2x/(1 + 1/(1/(1-x))) = 1 2x/(1 + 1-x) = 1 2x/(2-x) = 1 2x = 2-x 3x = 2 x = 2/3.Quiz of this QuestionPlease comment below if you find anything wrong in the above pos
1 min read