Solve the following quadratic equations by factorization:
Answers
Answered by
4
it is the answer...plz mark me as brainliest...
Attachments:
Answered by
0
Solution :
i ) 1/[(x-1)(x-2)]
= [(x-1)-(x-2)]/[(x-2)(x-1)]
= (x-1)/[(x-2)(x-1)] - (x-2)/[(x-2)(x-1)]
= 1/(x-2) - 1/(x-1) -----( 1 )
Similarly ,
ii ) 1/[(x-2)(x-3)]
= 1/(x-3) - 1/(x-2) ---( 2 )
iii ) 1/[(x-3)(x-4)]
= 1/(x-4) - 1/(x-3) ----( 3 )
Now ,
( 1 ) + ( 2 ) + ( 3 ) = 1/6
=> 1/(x-2) - 1/(x-1) + 1/(x-3) - 1/(x-2)
+ 1/(x-4) - 1/(x-3) = 1/6
After cancellation , we get
=> -1/(x-1) + 1/(x-4) = 1/6
=> [ -(x-4) + (x-1) ]/[ (x-1)(x-4) ] = 1/6
=> ( -x+4+x-1 )/( x²-5x+4) = 1/6
=> 3/(x²-5x+4) = 1/6
=> 18 = x² - 5x + 4
=> x² - 5x + 4 - 18 = 0
=> x² - 5x - 14 = 0
Splitting the middle term , we get
=> x² - 7x + 2x - 14 = 0
=> x( x - 7 ) + 2( x - 7 ) = 0
=> ( x - 7 )( x + 2 ) = 0
=> x - 7 = 0 or x + 2 = 0
=> x = 7 or x = -2
Therefore ,
x = 7 or x = -2
••••
i ) 1/[(x-1)(x-2)]
= [(x-1)-(x-2)]/[(x-2)(x-1)]
= (x-1)/[(x-2)(x-1)] - (x-2)/[(x-2)(x-1)]
= 1/(x-2) - 1/(x-1) -----( 1 )
Similarly ,
ii ) 1/[(x-2)(x-3)]
= 1/(x-3) - 1/(x-2) ---( 2 )
iii ) 1/[(x-3)(x-4)]
= 1/(x-4) - 1/(x-3) ----( 3 )
Now ,
( 1 ) + ( 2 ) + ( 3 ) = 1/6
=> 1/(x-2) - 1/(x-1) + 1/(x-3) - 1/(x-2)
+ 1/(x-4) - 1/(x-3) = 1/6
After cancellation , we get
=> -1/(x-1) + 1/(x-4) = 1/6
=> [ -(x-4) + (x-1) ]/[ (x-1)(x-4) ] = 1/6
=> ( -x+4+x-1 )/( x²-5x+4) = 1/6
=> 3/(x²-5x+4) = 1/6
=> 18 = x² - 5x + 4
=> x² - 5x + 4 - 18 = 0
=> x² - 5x - 14 = 0
Splitting the middle term , we get
=> x² - 7x + 2x - 14 = 0
=> x( x - 7 ) + 2( x - 7 ) = 0
=> ( x - 7 )( x + 2 ) = 0
=> x - 7 = 0 or x + 2 = 0
=> x = 7 or x = -2
Therefore ,
x = 7 or x = -2
••••
Similar questions