Tính giá trị của biểu thức

a	b	c	a × (b + c)	a × b + a × c
4	2	5	28	28
7	6	2
12	3	7
7	8	6

\[\begin{array}{l} \times \begin{array}{*{20}{c}}{\,\,\,\,\,\,36}\\{\underline {\,\,\,\,\,\,\,43} }\end{array}\\\,\,\,\,\,\,\,108\\\,\,\,\underline {1\,\,44\,\,\,} \\\,\,\,1\,\,548\end{array}\]

\[\begin{array}{l} \times \begin{array}{*{20}{c}}{\,\,\,\,\,123}\\{\underline {\,\,\,\,\,\,\,25} }\end{array}\\\,\,\,\,\,\,\,\,615\\\,\,\,\underline {2\,\,46\,\,\,} \\\,\,\,3\,\,075\end{array}\]

\[\begin{array}{l} \times \begin{array}{*{20}{c}}{\,\,\,\,245}\\{\underline {\,\,\,\,\,\,\,34} }\end{array}\\\,\,\,\,\,\,\,980\\\,\,\,\underline {7\,\,35\,\,\,\,} \\\,\,\,8\,\,330\end{array}\]