if x-8y=3 and x+y=4 what is the value of x and y?

$$\begin{gathered} x-8y = 3 ...\left(\mathrm{i}\right) \\ \mathrm{And} x + y = 4..\left(\mathrm{ii}\right) \end{gathered}$$
subtracting (ii) from (i) weget;
$$\begin{gathered} x-8y-x-y = 3-4 \\ \Rightarrow -9y = -1 \\ \Rightarrow y = \frac{1}{9} \end{gathered}$$
Now putting the value of y in (i) we get;
$$\begin{gathered} x+\frac{1}{9} = 4 \\ \Rightarrow x = 4-\frac{1}{9} \\ \Rightarrow x = \frac{35}{9} \end{gathered}$$