Share
|3x-2|=5 3\4+1\4:x=-2 {2\3} ²:{-8} – {-1\4+9\20}:9\5
Question
Leave an answer
Thạch Thảo
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Answers ( )
`| 3x – 2 | = 5`
`⇔` \(\left[ \begin{array}{l}3x – 2 = 5\\3x – 2 = -5\end{array} \right.\)
`⇔` \(\left[ \begin{array}{l}3x = 7\\3x = – 3\end{array} \right.\)
`⇔` \(\left[ \begin{array}{l}x = 7/3\\x = – 1\end{array} \right.\)
Vậy , `x ∈ { 7/3 ; – 1 }`
____________________________________________
`3/4 + 1/4 : x = – 2`
`⇔ 1/4 : x = – 2 – 3/4`
`⇔ 1/4 : x = -11/4`
`⇔ x = -11/4 : 1/4`
`⇔ x = -11`
Vậy , `x = -11`
_____________________________________________
`( 2/3 )^2 : ( – 8 ) – ( – 1/4 + 9/20 ) : 9/5`
`= 4/9 : ( – 8 ) – 1/5 : 9/5`
`= -1/18 – 1/9`
`= -1/6`
Đáp án:
ở dưới
nếu thấy hay thì cho mình xin
– 5 sao
– cám ơn
– hay nhất
Giải thích các bước giải:
|3x-2|=5
trường hợp 1 :
3x – 2 = 5
3x = 5 + 2
3x = 7
x = 7 : 3
x = $\frac{7}{3}$
trường hợp 2 :
3x – 2 = -5
3x = -5 + 2
3x = -3
x = -3 : 3
x = -1
vậy x ∈ { $\frac{7}{3}$ ; -1 }
$\frac{3}{4}$+$\frac{1}{4}$x=-2
$\frac{1}{4}$x = -2 – $\frac{3}{4}$
$\frac{1}{4}$x = $\frac{-11}{4}$
x = $\frac{-11}{4}$ : $\frac{1}{4}$
x= -11
vây x = -11
($\frac{2}{3}$) 2 : {-8} – {$\frac{-1}{4}$+$\frac{9}{20}$}:$\frac{9}{5}$
=$\frac{4}{9}$ . $\frac{-1}{8}$ – { $\frac{-5}{20}$ + $\frac{9}{20}$ . $\frac{5}{9}$
= $\frac{-4}{72}$ – $\frac{1}{5}$ . $\frac{5}{9}$
= $\frac{-1}{18}$ – $\frac{2}{18}$
= $\frac{1}{18}$