Question

Answer 1

`r)6/[x-3]=9/[2x-7]`

`=>6.(2x-7)=9.(x-3)`

`=>12x-42=9x-27`

`=>3x=15`

`=>x=5`

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`y)[-7]/[x+1]=6/[x+27]`

`=>-7.(x+27)=6.(x+1)`

`=>-7x-189=6x+6`

`=>13x=-195`

`=>x=-15`

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`z)3/[x-5]=[-4]/[x+2]`     `(x \ne 5;-2)`

`=>3(x+2)=-4.(x-5)`

`=>3x+6=-4x+20`

`=>7x=14`

`=>x=2` (t/m)

Answer 2

r)`6/(x-3) = 9/(2x-7)`

`=> 6(2x-7) =9(x-3)`

`12x - 42 = 9x -27`

`<=> 12x -42 -9x +27 =0`

`<=> 3x -15=0`

`=> 3x =15 => x =5`

y)`-7/(x+1) = 6/(x+27)`

`=> -7(x+27) = 6(x+1)`

`<=> -7x - 189 = 6x + 6`

`=> -7x -6x = 6+ 189`

`=> -13x =195`

`=> x = 195/-13 = -15`

z) `Đk : x ≠ 5 ; -2`

`3/(x-5) = (-4)/(x+2)`

`=> 3(x+2) = -4(x-5)`

`=> 3x+6 = -4x +20`

`<=> 3x + 4x =20 -6`

`=> 7x =14`

`=> x = 2(tm)`