Question

dupa 2 cresteri consecutive de pret prima de 10 % adoua de 15%  un obiect coasta 126.5 lei .care a fost pretul initial?

Answer 1

Fie x pretul initial
dupa prima scumpire:x+10% din x=x+10x/100=x+x/10=10x/10+x/10=11x/10
dupa a doua scumpire: 11x/10+15%din 11x/10=11x/10+15*11x/1000=11x/10+33x/200=  253x/200=126,5
x/200=0,5
x=200*0,5=100

Answer 2

    
$x=pretul\,\,initial \\ x*1,1*1,15=126,5 \\ x= \frac{126,5}{1,1*1,15}= \frac{126500}{11*115} =\frac{11*115*100}{11*115}=100\,\,Lei$