Răspuns :
prima zi(a) 10/100 * x
a doua zi(b) 30/100*x
a treia zi(c) 42
Calculezi
a+b+c=x
10x/100 + 30x/100 + 42=x
x/10 +3x/10 + 42 =x
x + 3x + 420 = 10 x
420= 10x-4x
420 =6x
x=420/6
x=70 Km
Cu placere
a doua zi(b) 30/100*x
a treia zi(c) 42
Calculezi
a+b+c=x
10x/100 + 30x/100 + 42=x
x/10 +3x/10 + 42 =x
x + 3x + 420 = 10 x
420= 10x-4x
420 =6x
x=420/6
x=70 Km
Cu placere