Giúp mik ạ mik dg gấp

Giải thích các bước giải:

a.$\dfrac13x-1.75-\dfrac73x=-1$ 

$\to \dfrac13x-\dfrac73x=1.75-1$

$\to -2x=0.75$

$\to x=-0.375$

b.$\dfrac34x-\dfrac38(x+1)=\dfrac12$

$\to \dfrac34x-\dfrac38x-\dfrac38=\dfrac12$

$\to \dfrac38x-\dfrac38=\dfrac12$

$\to \dfrac38x=\dfrac12+\dfrac38$

$\to \dfrac38x=\dfrac78$

$\to x=\dfrac73$

c.Ta có:

$(4x-\dfrac18)(x+2)>0$

$\to 4x-\dfrac18>0\to 4x>\dfrac18\to x>\dfrac1{32}$

Hoặc $x+2<0\to x<-2$

d.Ta có:

$(\dfrac{131313}{565656}+\dfrac{131313}{727272}+\dfrac{131313}{909090}):x=\dfrac15$

$\to (\dfrac{13}{56}+\dfrac{13}{72}+\dfrac{13}{90}):x=\dfrac15$

$\to \dfrac{39}{70}:x=\dfrac15$

$\to x=\dfrac{39}{14}$