$\\$
`e,`
`1 2/5 x + 3/5 (x-1)=3`
`-> 7/5x + 3/5x - 3/5=3`
`-> (7/5 + 3/5)x = 3 + 3/5`
`-> 2x =18/5`
`->x=18/5 : 2`
`->x=9/5`
Vậy `x=9/5`
$\\$
`f,`
`4/3 ( (-1)/2 +x^2) = 2 1/3`
`-> 4/3 ( (-1)/2 +x^2) = 7/3`
`-> (-1)/2 +x^2 = 7/3 : 4/3`
`-> (-1)/2 +x^2=7/4`
`-> x^2=7/4 -(-1)/2`
`->x^2=9/4`
`->` \(\left[ \begin{array}{l}x^2=(\dfrac{3}{2})^2\\x^2=(\dfrac{-3}{2})^2\end{array} \right.\) $\\$ `->` \(\left[ \begin{array}{l}x=\dfrac{3}{2}\\x=\dfrac{-3}{2}\end{array} \right.\)
Vậy `x=3/2` hoặc `x=(-3)/2`
