a)

I. $4-\square =3$, więc $\square =1$  

II. $\square -2=2$, więc $\square =4$

$\begin{array}{r}4,47\\ \underline{-2,13}\\ 2,34\end{array}$ 

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b)

I. $\square -2=7$, więc $\square =9$ 

II. $\square -3=9$, więc $12-3=9$, zatem $\square =2$

III. $4-\square =4$, więc $\square =0$

$\begin{array}{r}\stackrel{4}{\cancel{5}},\stackrel{12}{\cancel{2}}9\\ \underline{-0,32}\\ 4,97\end{array}$

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c)

I. $1-\square =6$, więc $11-\square =6$, zatem $\square =5$ 

II. $6-\square =5$, więc $\square =1$

III. $\square -1=0$, więc $\square =1$

$\begin{array}{r}1,\stackrel{6}{\cancel{7}}\stackrel{11}{\cancel{1}}\\ \underline{-1,15}\\ 0,56\end{array}$

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d)

I. $0-\square =4$, więc $10-\square =4$, zatem $\square =6$

II. $\left(\square -1\right)-7=2$, czyli $\square -8=2$, więc $10-8=2$, zatem $\square =0$

III. $7-5=\square$, więc $\square =2$ 

$\begin{array}{r}\stackrel{7}{\cancel{8}},\stackrel{9}{\cancel{0}}\stackrel{10}{\cancel{0}}\\ \underline{-5,76}\\ 2,24\end{array}$