Giải thích các bước giải:
Cau 1:
a)0,2-$\frac{3}{5}$ =$\frac{1}{5}$ - $\frac{3}{5}$=-$\frac{2}{5}$
b)$\frac{3}{8}$ .3$\frac{1}{3}$ =$\frac{3}{8}$.$\frac{10}{3}$ =$\frac{5}{4}$
c)4($\frac{-1}{2}$ )²+$\frac{1}{2}$ =4.$\frac{1}{4}$ +$\frac{1}{2}$ =1+$\frac{1}{2}$ =$\frac{3}{2}$
d)$\frac{1}{3}$ .$\frac{-4}{5}$ +$\frac{-6}{5}$ .$\frac{1}{3}$ =$\frac{1}{3}$ ($\frac{-4}{5}$+$\frac{-6}{5}$)=$\frac{1}{3}$.$\frac{-10}{5}$ =$\frac{-2}{3}$
Cau 2:
a)$\frac{x}{5}$ =$\frac{-4}{10}$
x=$\frac{-4.5}{10}$
x=$\frac{-20}{10}$
x=-2
b)|x|=0
⇒x=0
c)|x+1|=$\frac{2}{3}$
\(\left[ \begin{array}{l}x+1=2/3 \\x+1=-2/3\end{array} \right.\)
\(\left[ \begin{array}{l}x=-1/3\\x=-5/3\end{array} \right.\)
Chuc ban hoc gioi ^_^
