Un elev are o suma de bani.Dupa ce dubleaza aceasta suma cheltuieste 5 lei.Dubleaza suma ramasa si cheltuieste 10 lei.D4ubleaza din nou suma ramasa si cheltuieste 160 de lei.Elevul constata ca mai are 200 de lei.Calculati suma initiala.

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Răspunsuri

2014-11-15T19:19:28+02:00
X=suma initiala
[(x*2-5)*2-10]*2-160=200
[(x*2-5)*2-10]*2=360
(x*2-5)*2-10=180
(x*2-5)*2=190
x*2-5=95
x*2=100
x=50 lei

17 4 17
2014-11-15T19:20:59+02:00
[(a*2-5)*2-10]*2-160=200+160
[(a*2-5)*2-10]*2=360 :2
(a*2-5)*2-10=180 +10
(a*2-5)*2=190:2
a*2-5=95+5
a*2=100
a=100:2
a=50
50 de lei avea elevul la inceput


Sper ca te-am ajutat



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