giúp mik với ạ, mik vote 5* lun, thanks:
giúp mik với ạ, mik vote 5* lun, thanks:
Share
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
giúp mik với ạ, mik vote 5* lun, thanks:
Latifah
TH1: $\dfrac{3}{4}x-\dfrac{4}{5}=\dfrac{1}{2}$
$↔\dfrac{3}{4}x=\dfrac{1}{2}+\dfrac{4}{5}$
$↔\dfrac{3}{4}x=\dfrac{13}{10}$
$↔x=\dfrac{13}{10}:\dfrac{3}{4}$
$↔x=\dfrac{13}{10}.\dfrac{4}{3}=\dfrac{26}{15}$
TH2: $\dfrac{3}{4}x-\dfrac{4}{5}=-\dfrac{1}{2}$
$↔\dfrac{3}{4}x=-\dfrac{1}{2}+\dfrac{4}{5}$
$↔\dfrac{3}{4}x=\dfrac{3}{10}$
$↔x=\dfrac{3}{10}:\dfrac{3}{4}$
$↔x=\dfrac{3}{10}.\dfrac{4}{3}=\dfrac{2}{5}$
Mít Mít
Giải thích các bước giải:
`|3/4x-4/5|=1/2`
`⇔` \(\left[ \begin{array}{l}\dfrac{3}{4}x-\dfrac{4}{5}=\dfrac{1}{2}\text{(Với $x≥\dfrac{16}{15}$)}\\\dfrac{3}{4}x-\dfrac{4}{5}=-\dfrac{1}{2}\text{(Với $x<\dfrac{16}{15}$)}\end{array} \right.\)
`⇔` \(\left[ \begin{array}{l}\dfrac{3}{4}x=\dfrac{13}{10}\\\dfrac{3}{4}x=\dfrac{3}{10}\end{array} \right.\)
`⇔` \(\left[ \begin{array}{l}x=\dfrac{26}{15}(TM)\\x=\dfrac{2}{5}(TM)\end{array} \right.\)
$\text{Vậy $x∈\{\dfrac{2}{5};\dfrac{26}{15}\}$}$
Học tốt!!!