Răspuns:
ex3)
109+x=190
x=190-109
x=81
b)2+x-538=462
x=462+538=1000
x=2+?=1000
x=1000-2=998
×=998
v:2+998-538=462
c)(x:5)+7=15
X=?+7=15
X=?:5=8
X=8×5=40
d)5×X+3<17
5×1+3=8<17
5×2+3=10+3=13<17
problema 6)a+8×5=?:10=?-3=2
o luam de la coada spre capat
2+3=5
5×10=50
a+8×5=50
a=50-8×5=50-40
a=10
