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rezolva ecuatiile :
a)3(x+7)=75
14(12-x)=70

b)111+2x+29=10la puterea 3
5x+52-31=30 la puterea 2-19


Răspuns :

a) 3(x+7) =75
Folosim distributivitatea.
3x+3*7=75
3x+21=75
3x=75-21
3x=54
x=54:3
x=18

14(12-x)=70
Folosim distributivitatea
14*2-14x=70
28-14x=70
14x=70-28
14x=42
x=42:14
x=3

b)111+2x+29=10³
111+2x+29=1000
111+2x=1000-29
111+2x=971
2x=971+111
2x=1082
x=1082:2
x= 541