Teht 1.
a) 25 + X = 40 b) 18 + X = 28 c) 27 + X = 45 d) 53 + X = 60
X = 15 X = 10 X = 8 X = 7

teht 2.

a) X + 15 = 30 b) X + 30 = 100 c) X + 44 = 86 d) X + 65 = 95
X = 15 X = 70 X = 42 X = 30

teht 3.

a) 30 - X = 12 b) 25 - X = 18 c) 55 - X = 22 d) 100 - X = 32
X = 18 X = 17 X = 33 X = 68

teht 4.

a) X - 18 = 22 b) X - 30 = 15 c) X - 55 = 45 d) X - 89 = 5
X = 40 X = 45 X = 100 X = 94