Question

cine mă ajută vă rog din suflet

Answer 1

12

a)
4-4*10/100-=4-4/10=4-0,4=3,6


b) (20/100)*pix=6lei
(1/5)* pix=6lei
 pix initial=6*5=30 lei
 dupascumpire 30+6=36 lei



13
a)
 5/10=x/100=50/100  =50%


b)4/20=x/100
1/5=x/100
1/5=2/10=20/100=x/100
x=20



14 !!!!!v mai greu!!!!

x-30x/100=42
 100x/100-30x/100=42
 70x/100=42
7x/10=42
7x=420
x=420:7
x=60



b)
 x+25x/100=70
100x/100+25x/100=70
125x/100=70
25x/20=70
5x/4=70
5x=4*70
x=4*70:5
x=4*14
 x=56