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Aptitude - Surds and Indices - Discussion

Discussion Forum : Surds and Indices - General Questions (Q.No. 14)
Surds and Indices
14.
xb (b + c - a) . xc (c + a - b) . xa (a + b - c) = ?
xc xa xb
xabc
1
xab + bc + ca
xa + b + c
Answer: Option
Explanation:
Given Exp.
= x(b - c)(b + c - a) . x(c - a)(c + a - b) . x(a - b)(a + b - c)
= x(b - c)(b + c) - a(b - c)  .  x(c - a)(c + a) - b(c - a)
   .  x(a - b)(a + b) - c(a - b)
= x(b2 - c2 + c2 - a2 + a2 - b2)  .   x-a(b - c) - b(c - a) - c(a - b)
= (x0 x x0)
= (1 x 1) = 1.
Discussion:
22 comments Page 1 of 3.
Mayuran said:   1 decade ago
2nd step is confused. Please explain.
Dhanashree said:   1 decade ago
Little complicated sum please explain from 2nd step.
Mansi said:   1 decade ago
In the second step:

From the first term: x^(b-c)(b+c-a).

There are two brackets term, from the second bracket -a is taken out. As it comes out, it has to be multiplied by the first bracket.

So it gets multiplied and we get x^(b-c)(b+c)-a(b-c).

Similar thing is done for the rest.
(1)
Ganesh said:   1 decade ago
Second step is the simple representation through indices and hence in the third step the exponents are multiplied and again with the help of indices the sum is solved it is a very simple but tricky question.

Hope you understand my explanation. All the best.
Ammar said:   9 years ago
What does the dot (.) means between those numbers, help anybody?
Karan said:   9 years ago
Dot (.) is multiplication sigh you can use x or (.).
Gaurav joshi said:   9 years ago
X^(b-c)((b+c)-a).

We get, X^(b-c)(b+c)-a(b-c).

I hope we all get understand by this.
Susav karki said:   9 years ago
Can anyone explain the third step?
Ankit singhai said:   9 years ago
x^(b - c)(b + c - a) How it is possible?
Shivam Raj said:   8 years ago
Can anyone explain the 2nd step in easy solution?
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