   # What is the value of the folowing?

+1 vote
56 views

What is the value of:
(7 + sqrt(50))^(1/3) + (7 - sqrt(50))^(1/3)
[ Do not use calculator ] posted Nov 11, 2018
Share this puzzle

## 1 Answer

+1 vote

Best answer

2

I use here v instead of sqrt for better visibility:
7 + v50=7+5v2=1+3v2+6+2v2=(1+v2)^3 --->(1)
7 - v50=7-5v2=1-3v2+6-2v2=(1-v2)^3 ---> (2)
Using above equations in given one we get :
(1) ^(1/3)=1+v2
(2) ^(1/3)=1-v2
1+v2+1-v2=2 answer Nov 11, 2018

Similar Puzzles
0 votes

Aarav is 20 years older than Bhargav who is 5 times as old as Chetan.
The total of the ages of Aarav, Bhargav and Chetan is 174 years.
What is the value when the square of age of Bhargav is multiplied to the sum of ages of Aarav and Chetan?

+1 vote

If
6x - 4y = 8
8x = 5y + 13
Then what is the value of 6x - 3y?

0 votes

In quadrilateral ABCD, BC = CD. If ∠BAC = 3x, ∠BCA = x, ∠CAD = 5x, and ∠ACD = 3x, what is the value of x? 0 votes

If 49a^2 + 30ab + 25b^2 - 100ab = 289
then what is the value of
(2187)^a / (243)^b = ?