Tìm x a) -(-6)/12 + x=9/48 b)x - 4/6=5/25 + (-7)/15 c) x-4/5=6/20 + (-7)/3 d)-(-7)/5 + x=4/9

` Huy `

` a) -(-6)/12 + x = 9/48 `

` => 6/12 + x = 3/16 `

` => x = 3/16 - 6/12 `

` => x = 3/16 - 1/2 `

` => x = 3/16 - 8/16 `

` => x = (-5)/16 `

` b) x - 4/6 = 5/25 + (-7)/15 `

` => x - 2/3 = 1/5 + (-7)/15 = 3/15 + (-7)/15 = (-4)/15 `

` => x = (-4)/15 + 2/3 `

` => x = (-4)/15 + 10/15 `

` => x=6/15 -2/5 `

` c) x - 4/5 = 6/20 + (-7)/3 `

` => x - 4/5 = 18/60 + (-140)/60 `

` => x - 4/5 = (-122)/60=(-61)/30 `

` => x = (-61)/30 + 4/5 `

` => x = (-61)/30 + 24/30 `

` => x=(-37)/30 `

` d) -(-7)/5 + x = 4/9 `

` => 7/5 + x = 4/9 `

` => x= 4/9 - 7/5 `

` => x= 20/45 - 63/45 `

` => x=(-43)/45 `

Đáp án:

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