Aptitude - Simplification - Discussion

Discussion Forum : Simplification - General Questions (Q.No. 4)
4.
If a - b = 3 and a2 + b2 = 29, find the value of ab.
10
12
15
18
Answer: Option
Explanation:

2ab = (a2 + b2) - (a - b)2

   = 29 - 9 = 20

   ab = 10.

Discussion:
107 comments Page 5 of 11.

Venkat@rockzzzz said:   9 years ago
(a-b)^2 = a^2+b^2-2ab.
2ab = a^2+b^2-(a-b)^2,
= 29-3^2,
= 29-9,
2ab = 20.
ab =10.

Venkat@rockzzzz said:   9 years ago
(a-b)^2 = a^2+b^2-2ab.
2ab = a^2+b^2-(a-b)^2,
= 29-3^2,
= 29-9,
2ab = 20.
ab =10.

Govind said:   8 years ago
If a+b+c=0 then {(a^2 + b^2 + c^2)^2} / {(a^2 * b^2) + (b^2 * c^2) + (c^2 * a^2)}.

Harsh singh said:   9 years ago
Yes @Bonjor.

(a+b)2 = (a-b)2+4ab,
(a+b)2 = 256,
a+b = +-16.
+-16 is the answer.

Gyanika said:   9 years ago
Can somebody please solve this question.

a - b = 1, 2a + 20 = b. Then a, b is?

Francium said:   9 years ago
Guys, please solve this for me a2 + b2 = 36 and an=7 find the value of (a+b)2.

Imane said:   8 years ago
What about if its: find the value of a and b and we have just a+b=2 and ab=-5?

Anil malav said:   9 years ago
(a^2 + b^2)^1/2 = 613 then find the value of a+b.

Solve and find the answer.

MBA P said:   8 years ago
If a * b = 3a - 2b.
Find (4*2)*7 WHAT DOES THIS MEAN?
EXPLAIN ME PLEASE.

Raman deep said:   8 years ago
If (2-a+b, b)=(6, 2), then find the value of a and b. Can anyone solve this?


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