\(\dfrac{x-1}{45}-\dfrac{x-6}{40}=0\\ \Rightarrow\dfrac{8\left(x-1\right)}{360}-\dfrac{9\left(x-6\right)}{360}=0\\ \Rightarrow\dfrac{8x-8-9x+54}{360}=0\\ \Rightarrow-x+46=0\\ \Rightarrow-x=-46\\ \Rightarrow x=46\)

\(\dfrac{11}{19}+\dfrac{19}{18}+\dfrac{8}{19}-\dfrac{1}{18}+5,2\\ =\left(\dfrac{11}{19}+\dfrac{8}{19}\right)+\left(\dfrac{19}{18}-\dfrac{1}{18}\right)+\dfrac{26}{5}\\ =\dfrac{19}{19}+\dfrac{18}{18}+\dfrac{26}{5}\\ =2+\dfrac{26}{5}\\ =\dfrac{10}{5}+\dfrac{26}{5}\\ =\dfrac{36}{5}\\ \left(-\dfrac{7}{9}+\dfrac{3}{11}\right):\dfrac{3}{4}-\left(\dfrac{2}{9}-\dfrac{19}{11}\right):\dfrac{3}{4}\\ =\left(-\dfrac{7}{9}+\dfrac{3}{11}-\dfrac{2}{9}+\dfrac{19}{11}\right):\dfrac{3}{4}\\ =\left[\left(-\dfrac{7}{9}-\dfrac{2}{9}\right)+\left(\dfrac{3}{11}+\dfrac{19}{11}\right)\right]:\dfrac{3}{4}\\ =\left(-\dfrac{9}{9}+\dfrac{22}{11}\right)\cdot\dfrac{4}{3}\\ =\left(-1+2\right)\cdot\dfrac{4}{3}\\ =\dfrac{4}{3}\)

`a, 1/7 -x=0,5`

`=>x= 1/7 - 1/2`

`=> x= 2/14 - 7/14`

`=> x= -5/14`

__

`b,1/2 +2/3 x =4/5`

`=> 2/3x = 4/5 -1/2`

`=> 2/3 x= 8/10 - 5/10`

`=> 2/3x = 3/10`

`=> x= 3/10 : 2/3`

`=> x= 3/10 xx 3/2`

`=> x= 9/20`

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`d,x/5 = 5/6 + (-19)/30`

`=> x/5 = 25/30 + (-19)/30`

`=>x/5= 6/30`

`=> x/5= 1/5`

`=>x=1`

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`f, 3/5 x +1/5=1/6`

`=> 3/5 x =1/6 -1/5`

`=>3/5 x= 5/30 - 6/30`

`=> 3/5 x=-1/30`

`=> x= -1/30 : 3/5`

`=> x= -1/30 xx 5/3`

`=> x= -5/90= -1/18`

ờ kệ e=))) hỏi cho hay-)

e dth quá tr à, em ăn cơm chưa=))))