Aptitude - Simplification - Discussion

Discussion Forum : Simplification - General Questions (Q.No. 14)
14.
(469 + 174)2 - (469 - 174)2 = ?
(469 x 174)
2
4
295
643
Answer: Option
Explanation:

Given exp. = (a + b)2 - (a - b)2
ab

   = 4ab
ab

   = 4 (where a = 469, b = 174.)

Discussion:
15 comments Page 1 of 2.

Amrit said:   1 decade ago
Its very simple.
Its formula,

[(a+b)^2-(a-b)^2]/ab.

[(a^2+b^2+2ab)-(a^2+b^2-2ab)]/ab.

[a^2+b^2+2ab-a^2-b^2+2ab]/ab.

From here a^2-a^2 = 0, b^2-b^2 = 0, and 2ab+2ab = 4ab.

4ab/ab.

Now divide ab/ab i.e 1.

so 4*1 = 4.
(4)

Navya said:   1 decade ago
It's simple yar.

(a+b)^2-(a-b)^2/ab its actual formula.

By solving (a+b)^2 = a^2+2ab+b^2 and (a-b)^2 = a^2-2ab+b^2.

By substituting in the above formula we can easily get answer ok its very simple yar.
(3)

Kalyan said:   5 years ago
Formula is a^2-b^2 = (a+b)(a-b).
Here a= 469+174,b = 469-174.
Substitute in formula:

= (469+174+469-174)(469+174-469+174)/469*174.
= 2*469*2*174/469*174,
= 4*469*174/469*174,
= 4.
(4)

Harsh Kadam said:   3 years ago
We can also do it directly using (a+b) ^2 formula. And a-b^2 formula.
Taking 469*174 common. Then it gets divided by the denominator. After solving brackets. We get 4.

Naddy said:   1 decade ago
=[(a+b)^2-(a-b)^2]/ab
=[(a2+b2+2ab)-(a2-b2-2ab)]/ab
=4ab/ab,
where as a^2 and b^2 will get cancelled as both are in oppoaite signs
=4

Afroz said:   1 decade ago
I did not come to know how 4ab has come as a answer so kindly send me the suggestion where I get answer.

Laxata said:   8 years ago
I am not yet getting this.

Please solve this problem.
(2)

SHAIK ABDUL SALEEM said:   1 year ago
Very useful, Thanks all for explaining the answer.

Abarna said:   9 years ago
@Amrit.

Very clear explanation. Thank you.

Divya said:   4 years ago
Thanks for your nice explanation @Navya.
(1)


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