Request a call back

Join NOW to get access to exclusive study material for best results

CBSE Class 9 Answered

IF
Asked by studdybuddy | 29 Sep, 2008, 07:34: PM
Expert Answer

(x+y)3 = x3 +y3 +3xy(x+y)

(x+y)3 = 5+3xy(x+y)..............(1)

now

x2+y2=3

(x2+y2 )(x+y) = 3(x+y)

x3 +y3 +xy(x+y) = 3(x+y)

5+xy(x+y)= 3(x+y)

xy(x+y)= 3(x+y) -5.....(2)

now put value of xy(x+y) in(1) from (2)

(x+y)3 = 5+3( 3(x+y) -5 )

(x+y)3 -9(x+y) +10=0

let x+y =t

after solving this qubic equation

we get (t-2)(t2+2t+5) = 0

since t2+2t+5= (t+1)2+4>0 ( always positive)

so t-2=0

t=2 ==> x+y=2

Answered by | 14 Dec, 2008, 02:20: AM
CBSE 9 - Maths
Asked by poornimaram165 | 30 Jul, 2022, 08:46: AM
ANSWERED BY EXPERT
CBSE 9 - Maths
Asked by manishgupta8980 | 15 Jul, 2022, 09:17: PM
ANSWERED BY EXPERT
CBSE 9 - Maths
Asked by lovebagri455 | 14 Jul, 2022, 04:56: PM
ANSWERED BY EXPERT
CBSE 9 - Maths
Asked by UTKARSH.CHANDRA.02008 | 09 Jul, 2022, 09:54: AM
ANSWERED BY EXPERT
CBSE 9 - Maths
Asked by avani2713 | 08 Jul, 2022, 01:52: AM
ANSWERED BY EXPERT
CBSE 9 - Maths
Asked by zbano7424 | 07 Jul, 2022, 08:18: PM
ANSWERED BY EXPERT
CBSE 9 - Maths
1*1
Asked by muradesrushti66 | 06 Jul, 2022, 08:50: PM
ANSWERED BY EXPERT
CBSE 9 - Maths
Asked by yeshudarsh | 05 Jul, 2022, 06:38: PM
ANSWERED BY EXPERT
CBSE 9 - Maths
Asked by jahnavinehra | 03 Jul, 2022, 11:19: AM
ANSWERED BY EXPERT
CBSE 9 - Maths
Asked by sumitrasangwa041 | 02 Jul, 2022, 02:21: PM
ANSWERED BY EXPERT

Start your hassle free Education Franchisee and grow your business!

Know more
×