Aflati numarul j repede va rog ca e ora 10 si nu mai pot!

i) 54:i=7+7-5
54:i=9
i=54:9i=6
j) (30+4 x j-8):6=7
(22+4 x j):6=7
22 + 4 x j=6 x 7
4 x j=42-22
4 x j=20
j= 20:4
j=5
k) (64-32-12:k)-(40-20)=9
(32-12:k) - 20=9
32-12:k-20=9
12-12:k=9
12:k=12-9
12:k=3
k=12:3
k=4
l) (95-45-9 x l).8=36-32
(50-9 x l):8=4
50-9 x l=4 x 8
50-9 x l=32
9 x l =50-32
9 x l=18
l=18:9
l=2