3)Media semestriala=(7+910)/3=26/3=8,66...=8,(6)
4)a) 9/4·16/8:2intreg1/6=
9/4·2/1:(2·6+1)/6=
18/4:13/6=
9/2·6/13=9/1·3/13=27/13
b)(4/5)¹³:[(4/5)²]⁶=
(4/5)¹³:(4/5)¹²=
(4/5)¹³⁻¹²=4/5
5)x=0,1,2,3,4,5
ca fractia sa fie supraunitara x poate lua valori de la 0 la 5
6)3/2<(a+1)/6
3·6<2(a+1)
18<2a+2 :2
9<a+1
-a<1-9
-a<-8 inmultim -1
a>8
(a+1)/6<53/60
60(a+1)<6·53
60a+60<318
60a<318-60
60a<258
a<258/60
a<4,3
ceva e gresit in enunt
7)Mp=(4·4+10··9,6)/(4+10)=(16+96)/14=112/14=8
deci un caiet costa in medie 8 lei
8)x-suma initiala
I zi: x-2x/5=(5x-2x)/5=3x/5
II zi: 3x/5-3x/5·1/2=3x/5-3x/10=(6x-3x)/10=3x/10
3x/10=15
x=(10·15)/3=150/3=50 lei suma initiala
I zi a cheltuit: 50·2/5=100/5=20 lei
II zi a cheltuit: (50-20):2=30:2=15 lei
20lei+15lei+15lei=50 lei
