If a^2−b^2=2352 and a^2+b^2=14210 then what is the value of 13ab?

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23 Jan 2018 Find the Value

If a^2−b^2=2352 and a^2+b^2=14210 then what is the value of 13ab?

OPtion

1) 19091
2) 91019
3) 91891
4) 91091
5) 19019
6) 91191
7) 91691
8) 91391
9) 91819
10) None of these

Solution

As per question
a^2 - b^2 = 2352 ...(1)
a^2 + b^2 = 14210...(2)

Adding (1) and (2), we get
2a^2 = 16562
=> a^2 = 8281
=> a = 91

Substracting (1) from (2), we get
2b^2 = 11858
=> b^2 = 5929
=> b = 77

23*a*b= 13*91*77 = 91091

Correct Option: 4 Best Solution (0)