Đáp án:

Giải thích các bước giải:

 ` 1) `

` ( 1 )/( x ) + ( 1 )/( 2x ) = 3/2 `    ` ( x \ne 0 ) `

` <=> ( 2 )/( 2x ) + ( 1 )/( 2x ) - ( 3x )/( 2x ) = 0 `

` => 2 + 1 - 3x = 0 `

` <=> 3x = 3 `

` <=> x = 1 ( TM  ) `

Vậy ` x = 1 `

` 4) `

` 1/x - ( 3 )/( 2x ) = 1/5`         ` ( x \ne 0 ) `

` ( 10 )/( 10x ) - ( 15 )/( 10x ) - ( 2x )/( 10x ) = 0 `

` => 10 - 15 - 2x = 0 `

` <=> 2x = -5 `

` <=> x = -5/2( TM )  `

Vậy ` x = -5/2 `

` 7) `

` ( 1 )/( 2x ) + ( 3 )/( 4x ) = ( 5 )/( 2x^2 ) `       ` ( x \ne 0 ) `

` <=> ( 2x )/( 4x^2 ) + ( 3x )/( 4x^2 ) - ( 10 )/( 4x^2 ) = 0 `

` => 2x + 3x - 10 = 0 `

` <=> 5x = 10 `

` <=> x = 2 ( TM ) `

Vậy` x = 2 `

` 10) `

` ( 5 )/( x + 2 ) = 3 `     ` ( x \ne -2 ) `

` <=> ( 5 )/( x + 2 ) - ( 3( x + 2 ) )/( x + 2 ) = 0 `

` => 5 - 3( x + 2 ) = 0 `

` <=> 5 - 3x - 6 = 0 `

` <=> 3x = -1 `

` <=> x = -1/3 ( TM ) `

Vậy ` x = -1/3 `

` 13) `

` ( x )/( x + 5 ) = 2 `       ` ( x \ne -5 ) `

` <=> ( x )/( x + 5 ) - ( 2( x + 5 ) )/( x + 5 ) = 0 `

` => x - 2( x + 5 )  =0 `

` <=> x - 2x - 10 = 0 `

` <=> x = -10 ( TM ) `

Vậy ` x = -10 `