Aptitude - Surds and Indices - Discussion
Discussion Forum : Surds and Indices - General Questions (Q.No. 2)
2.
| If |  |
a |  |
x - 1 | = | |
b | |
x - 3 | , then the value of x is: |
| b | a |
Answer: Option
Explanation:
| Given |
a | |
x - 1 | = | |
b | |
x - 3 |
| b | a |
 |
|
a | |
x - 1 | = | |
a | |
-(x - 3) | = | |
a | |
(3 - x) |
| b | b | b |
x - 1 = 3 - x
2x = 4
x = 2.
Discussion:
26 comments Page 3 of 3.
Rakesh KIIT said:
1 decade ago
(a/b)^x-1=(b/a)^x-3
can be written as :
After cross multiplication :
(a)^(2x-4)=(b)^(2x-4)
=>(a/b)^(2x-4)=1
=>(a/b)^(2x-4)=(a/b)^0
=> 2x-4=0
=>x=4/2
=>x=2
can be written as :
After cross multiplication :
(a)^(2x-4)=(b)^(2x-4)
=>(a/b)^(2x-4)=1
=>(a/b)^(2x-4)=(a/b)^0
=> 2x-4=0
=>x=4/2
=>x=2
Yashi Jain said:
1 decade ago
How could you add the powers when there is an = sign between the two.
Nisikanta said:
1 decade ago
(a/b)^x-1= (b/a)^x-3
* Remember, sinplification is always solved by 2 or more fraction or number or alphabet.
:If the alphabet fraction is not equal to one anthor,we have reranged it.
= (a/b)^x-1= (a/b)^-(x-3)= (a/b)^(3-x)
: Then we have to take power for simplification.
= x-1= 3-x
* When the number goes after or before '=' sign the sign changes
: Now we have to change the places.
= 2x=4
=x=2
* Remember, sinplification is always solved by 2 or more fraction or number or alphabet.
:If the alphabet fraction is not equal to one anthor,we have reranged it.
= (a/b)^x-1= (a/b)^-(x-3)= (a/b)^(3-x)
: Then we have to take power for simplification.
= x-1= 3-x
* When the number goes after or before '=' sign the sign changes
: Now we have to change the places.
= 2x=4
=x=2
Basavaraju said:
1 decade ago
I can not understand.
Nem prasad said:
1 decade ago
Can anybody tell me what is the concept through which this problem has been solved ?
Ravi kiran said:
1 decade ago
@pooja
(b/a) can be written as (a/b)^-1.
Based on this concept this problem is solved.
(b/a) can be written as (a/b)^-1.
Based on this concept this problem is solved.
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