a)
a + 34 : 2 + 28 : 14 = 44
a + 17 + 2 = 44
a = 44 - 2 -17 → metoda mersului invers
a = 25
b)
65 : 5 + a × 3 - 39 : 13 = 78
13 + a × 3 - 3 = 78
13 + a × 3 = 78 + 3
13 + a × 3 = 81
a × 3 = 81 - 13
a ×3 = 68
a = 68 : 3
a = 22,(6)
b) iar daca raspunsul este 79
65 : 5 + a × 3 - 39 : 13 = 79
13 + a x 3 - 3 = 79
a x 3 = 79 + 3 - 13
a x 3 = 82 - 13
a x 3 = 69
a = 69 : 3
a = 23