a)2x+1:0,125=-4^2 ; b)/x//20=7/10+-13/20 29/08/2021 Bởi Madeline a)2x+1:0,125=-4^2 ; b)/x//20=7/10+-13/20
Đáp án + Giải thích các bước giải: a) $2x + 1 : 0,125 = (-4)^2$ $2x + 8 = 16$ $2x = 16 – 8$ $2x = 8$ $x = 8:2$ $x = 4$ b) $\bigg|\dfrac{x}{20}\bigg| = \dfrac{7}{10} + \dfrac{-13}{20}$ $\bigg|\dfrac{x}{20}\bigg| = \dfrac{14}{20} + \dfrac{-13}{20}$ $\bigg|\dfrac{x}{20}\bigg| = \dfrac{1}{20}$ \(=>\left[ \begin{array}{l}\dfrac{x}{20} = \dfrac{1}{20}\\\dfrac{x}{20} = \dfrac{-1}{20}\end{array} \right.\) \(=>\left[ \begin{array}{l}x=1\\x=-1\end{array} \right.\) Vậy $x \in \left\{1, -1\right\}$ Bình luận
`a, 2x + 1 : 0,125 = ( – 4 )^2` `⇔ 2x + 8 = 16` `⇔ 2x = 16 – 8` `⇔ 2x = 8` `⇔ x = 8 : 2` `⇔ x = 4` Vậy , `x = 4` `b, | x |/20 = 7/10 + (-13)/20` `⇔ | x |/20 = 14/20 + (-13)/20` `⇔ | x |/20 = 1/20` `⇔` \(\left[ \begin{array}{l}x = 1\\x = – 1\end{array} \right.\) Vậy , `x ∈ { 1 ; – 1 }` Bình luận
Đáp án + Giải thích các bước giải:
a)
$2x + 1 : 0,125 = (-4)^2$
$2x + 8 = 16$
$2x = 16 – 8$
$2x = 8$
$x = 8:2$
$x = 4$
b)
$\bigg|\dfrac{x}{20}\bigg| = \dfrac{7}{10} + \dfrac{-13}{20}$
$\bigg|\dfrac{x}{20}\bigg| = \dfrac{14}{20} + \dfrac{-13}{20}$
$\bigg|\dfrac{x}{20}\bigg| = \dfrac{1}{20}$
\(=>\left[ \begin{array}{l}\dfrac{x}{20} = \dfrac{1}{20}\\\dfrac{x}{20} = \dfrac{-1}{20}\end{array} \right.\)
\(=>\left[ \begin{array}{l}x=1\\x=-1\end{array} \right.\)
Vậy $x \in \left\{1, -1\right\}$
`a, 2x + 1 : 0,125 = ( – 4 )^2`
`⇔ 2x + 8 = 16`
`⇔ 2x = 16 – 8`
`⇔ 2x = 8`
`⇔ x = 8 : 2`
`⇔ x = 4`
Vậy , `x = 4`
`b, | x |/20 = 7/10 + (-13)/20`
`⇔ | x |/20 = 14/20 + (-13)/20`
`⇔ | x |/20 = 1/20`
`⇔` \(\left[ \begin{array}{l}x = 1\\x = – 1\end{array} \right.\)
Vậy , `x ∈ { 1 ; – 1 }`