Răspuns :
Răspuns:
Z1=30℅×x= 30/100×x
z2= 2/5×70/100
z3=42 km
30/100×x+2/5×70/100×x+42=x
3/10×x+14/50×x+42=x |×50
15x+14x+2100=50x
29x+2100= 50x
29x+2100=50x
29x-50x=-2100
-21x= -2100
x=-2100:(-21)
x=100 km
Răspuns:
Z1=30℅×x= 30/100×x
z2= 2/5×70/100
z3=42 km
30/100×x+2/5×70/100×x+42=x
3/10×x+14/50×x+42=x |×50
15x+14x+2100=50x
29x+2100= 50x
29x+2100=50x
29x-50x=-2100
-21x= -2100
x=-2100:(-21)
x=100 km