$\begin{array}{l}\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}2+\phantom{\rule{0.147em}{0ex}}3\cdot 8-4:4=\\ =2+24-4:4=\\ =2+24-1=\\ =26-1=\\ =\underset{¯}{\underset{¯}{25}}\end{array}$    $\begin{array}{l}1\right)\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}3\cdot 8=24\\ 2\right)\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}4:4=1\\ 3\right)\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}2+24=26\\ 4\right)\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}26-1=25\\ \end{array}$
$\begin{array}{l}\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}2+\phantom{\rule{0.147em}{0ex}}3\cdot \left(8-4\right):4=\\ =2+3\cdot 4:4=\\ =2+12:4=\\ =2+3=\\ =\underset{¯}{\underset{¯}{5}}\end{array}$    $\begin{array}{l}1\right)\phantom{\rule{0.147em}{0ex}}8-4=4\\ 2\right)\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}3\cdot 4=12\\ 3\right)\phantom{\rule{0.147em}{0ex}}12:4=3\\ 4\right)\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}2+3=5\\ \end{array}$
$\begin{array}{l}\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}\left(2+\phantom{\rule{0.147em}{0ex}}3\right)\cdot 8-4:4=\\ =5\cdot 8-4:4=\\ =40-4:4=\\ =40-1=\\ =\underset{¯}{\underset{¯}{39}}\end{array}$    $\begin{array}{l}1\right)\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}2+3=5\\ 2\right)\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}5\cdot 8=40\\ 3\right)\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}4:4=1\\ 4\right)\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}40-1=39\\ \end{array}$