Expanding Brackets

Question 1:

8 r9
8r72

Question 2:

6 7z9
42z54

Question 3:

6 5g6
30g36

Question 4:

a 10a+3
10a2+3a

Question 5:

j 8n+7
8jn+7j

Question 6:

6j 7j+2v
42j2+12jv