1) 103 + 108=x
x = 211
2) a + a + 1 + a+ 2 = 21
3a = 21 - 3
3a = 18
a = 18 : 3
a = 6
nr. din mijloc este a + 1 = 7
3) cant. consumata luni - a
cant. consumata marti - b
cant. consumata miercuri - c
a - 34 = b
c = 20
b : 5 = c = 20
b = 20 * 5
b = 100
a - 34 = 100
a = 100 + 34
a = 134
4) x+19>42*4
x+19>168
x>168-19
x>149
x=150