Đáp án + Giải thích các bước giải:
`a,`
`12 - |x + 2| = 10`
`⇒|x + 2| = 12 - 10`
`⇒|x + 2| =2`
`⇒`\(\left[ \begin{array}{l}x + 2 = 2\\x + 2 = -2\end{array} \right.\)
`⇒` \(\left[ \begin{array}{l}x=0\\x=-4\end{array} \right.\)
`b,`
`1/2 . x + 150%x = 2020`
`⇒ 1/2 . x + 3/2.x= 2020`
`⇒x . (1/2 + 3/2) = 2020`
`⇒x . 2 = 2020`
`⇒x = 2020 ÷ 2`
`⇒x = 1010`
`c,`
`(-5)/4 - x = 1/16`
`⇒x = (-5)/4 - 1/16`
`⇒x = (-20)/16 - 1/16`
`⇒x = (-21)/16`
`d,`
`(3/7 . x + 1) ÷ (-4) = (-1)/28`
`⇒3/7 .x + 1= (-1)/28 . (-4)`
`⇒3/7.x + 1 = 1/7`
`⇒3/7.x = 1/7 - 1`
`⇒3/7.x = 1/7 - 7/7`
`⇒3/7.x = (-6)/7`
`⇒x = (-6)/7 : 3/7`
`⇒x = (-6)/7 . 7/3`
`⇒x = - 2`
