I zi+35 =x
I zi:
30%*x=[tex] \frac{30x}{100} [/tex]
[tex] \frac{30x}{100} +35=x
[/tex]
Amplifici 35 cu 100 ca sa ai numitor comun:
[tex] \frac{30x}{100} + \frac{35*100}{100}=x [/tex]
[tex] \frac{30x+3500}{100} =x[/tex]
Prin regula de trei simpla:
30x+3500=100*x
30x+3500=100x
100x-30x=3500
70x=3500
x=3500/70
x=50 lei
