Răspuns :
1) 7×3 - a = 14
21 - a = 14
21 - 14 = a
a = 21 - 14
a = 7
2) 2×9 + b = 61
18 + b = 61
b = 61 - 18
b = 43
3) c + 4 - 8 = 21
c = 21 - 4 + 8
c = 17 + 8
c = 25
21 - a = 14
21 - 14 = a
a = 21 - 14
a = 7
2) 2×9 + b = 61
18 + b = 61
b = 61 - 18
b = 43
3) c + 4 - 8 = 21
c = 21 - 4 + 8
c = 17 + 8
c = 25
7x3-a=14
21-a=14
a=21-14
a=7
8x4+x=49
32+x=49
x=49-32
x=17
2x9+b=61
18+b=61
b=61-18
b=43
c+4-8=21
c+4=21+8
c+4=29
c=29-4
c=25
21-a=14
a=21-14
a=7
8x4+x=49
32+x=49
x=49-32
x=17
2x9+b=61
18+b=61
b=61-18
b=43
c+4-8=21
c+4=21+8
c+4=29
c=29-4
c=25