Solve for each system: 3b+c+3u = 22, 3b+6c = 12, 5b=10

5b=10

5b/5=10/5

b=2

3b+6c = 12

3(2)+6c = 12

6+6c = 12

6+6c-6= 12-6

6c=6

6c/6=6/6

c=1

3b+c+3u = 22

3(2)+1+3u = 22

6+1+3u = 22

7+3u = 22

7+3u-7 = 22-7

3u=15

3u/3=15/3

u=5