Răspuns:
2[3I2x-3I-8]-9=5
2[3I2x-3I-8]=9+5
3I2x-3I-8=14:2
3I2x-3I=7+8
I2x-3I=15:3
I2x-3I=5
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2x-3=5 2x=8 x=4
-2x+3=5 }sistem =>-2x=2 }=>x=-1 }
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10%dinx= 10x/100=x/10 -prima crestere
x+x/10=10x/10+x/10=11x/10 -noul pret
15%din11x/10=15/100·11x/10=33x/200- a doua crestere
33x/200= 2 277
33x=200·2 277
x=455400:33
x=13800lei