Đáp án + Giải thích các bước giải:
f, `2/3 x - 1/2 x = 5/12`
` x . (2/3 - 1/2) = 5/12`
` x . ( 4/6 - 3/6) = 5/12`
` x . 1/6 = 5/12`
` x = 5/12 : 1/6`
` x = 5/2`
Vậy `x = 5/2`
g, `1/2 x - 1 1/3 = 2/3`
` 1/2 x - 4/3 = 2/3`
` 1/2 x = 2/3 + 4/3`
` 1/2 x = 2`
` x = 2 : 1/2`
` x = 4`
Vậy `x = 4`
h, `2/3 x - 1/2x = 5/12` (Trùng với câu f)
` x . (2/3 - 1/2) = 5/12`
` x . 1/6 = 5/12`
` x = 5/12 : 1/6`
` x = 5/2`
Vậy `x = 5/2`
i, `(2/3 x - 1/2 x + x) : 1/5 = -35/6`
` x(2/3 - 1/2 + 1) = -35/6 xx 1/5`
` x(4/6 - 3/6 + 6/6) = -7/6`
` x . 7/6 = -7/6`
` x = -7/6 : 7/6`
`x = -1`
Vậy `x = -1`
j, `2|3 - x| - 5 = 3`
`2|3 - x| = 3 + 5`
` 2|3 - x| = 8`
`|3 - x| = 8 : 2`
`|3 - x| = 4`
⇒\(\left[ \begin{array}{l}3 - x = 4\\3 - x = -4\end{array} \right.\)
⇒\(\left[ \begin{array}{l}x = 3 - 4\\x = 3 - (-4)\end{array} \right.\)
⇒\(\left[ \begin{array}{l}x = -1\\x = 7\end{array} \right.\)
Vậy `x \in {-1 ; 7}`
