not sure how the format is for the question but i think its
for the second column: y=2+2, y=6+2, y=7+2
for third column: 4, 8, 9
for the fourth column: (2,4), (6,8), (7,9)
for the according to the table:
(6,8), when his brother is 6 he is 8
for the graph: graph out the points (2,4), (6,8), (7,9)
another solution can be when he is 5 his brother is 3
(these should be right)