C și d mersi mult dau coroana
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c) 10[10+(10x+10)]=10^3
10+(10x+10)=10^3:10
10+(10x+10)=10^2
10x+10=100-10
10x+10=90
10x=90-10
10x=80
x=80:10
x=8
d)[(3+x:2):11+7]*5-13=37
[(3+x:2):11+7]*5=37+13
[(3+x:2):11+7]=50:5
(3+x:2):11+7=10
(3+x:2) :11=3
3+x:2=3*11
x:2=33-3
x=30:2
x=15