tìm x a) x – 5/6 = 11/13 b) 15/16 – x = 1/12 + 2/5 c) 7/8 + 8/9 = x – 1/2 d) 13/12 – 5/7 = x – 6/7 e) x – 1/2 = 16/7 – x

a, `x -5/6=11/13`

`=> x = 11/13+5/6`

`=> x = 66/78+65/78`

`=> x = 131/78`

b) `15/16 – x = 1/12 + 2/5`

`=> 15/16-x = 5/60+24/60=29/60`

`=> x=15/16-29/60`

`=> x=225/240 – 116/240`

`=> x = 109/240`

c)`  7/8 + 8/9 = x – 1/2`

`=> x-1/2 = 63/72+64/72`

`=> x-1/2=127/72`

`=> x=127/72+36/72`

`=> x=163/72`

d) `13/12 – 5/7 = x – 6/7`

`=> x = 13/12-5/7+6/7`

`=> x=13/12+1/7`

`=> x=91/84+12/84`

`=> x=103/84`

e, `  x – 1/2 = 16/7 – x `

`=> 2x=16/7+1/2`

`=> 2x= 32/14+7/14`

`=> 2x=39/14`

`=> x=39/28`