Question

Rezolvati urmatoarele exercit: (729+x):2=870 ; [(b-8000):50+900]:250=4 ; [(x-1):100+90]:10-10=0 ; 160:8+800:5=x:3-480:4 ; [(x+428:4)X2+5]x2-186=800

Answer 1

(729+x):2=870
(729+x)=870x2
729+x=1740
x=1740-729
x=1011

[(b-8000):50+900]:250=4
[(b-8000):50+900]=4x250
[(b-8000):50+900]=1000
(b-8000):50=1000-900
(b-8000):50=100
b-8000=100x50
b-8000=5000
b=5000+8000
b=13000


[(x-1):100+90]:10-10=0
[(x-1):100+90]:10=0+10
[(x-1):100+90]:10=10
(x-1):100+90=10x10
(x-1):100+90=100
(x-1):100=100-90
(x-1):100=10
x-1=10x100
x-1=1000
x=1000+1
x=1001

160:8+800:5=x:3-480:4
20+160=x:3-120
180=x:3-120
x:3=180+120
x:3=300
x=300x3
x=900

[(x+428:4)X2+5]x2-186=800
[(x+107)X2+5]x2=800+186
[(x+107)x2+5]x2=986
(x+107)x2+5=986:2
(x+107)x2+5=493
(x+107)x2=493-5
(x+107)x2=488
x+107=488:2
x+107=244
x=244-107
x=137