3.suma a 4 numere consecutive este 448.Care sunt numerele?
a+b+c+d=448
a,b,c,d= nr naturale consecutive IMPARE
scriem matematic:
a+b+c+d=448
b=a+2
c=b+2=a+4
d=c+2=b+6
a+b+c+d=a+a+2+a+4+a+6=4a+12
4a+12=448
a=(448-12)/4=109
a=109
b=111
c=113
d=115
4.
a |-----|-----|-----|-----|12|
b |-----|
135 - 12 = 123 ( diferenta de 3 segmente)
123 : 3 = 41 (b)
41 × 4 +12 = 176 (a)
Verificare: 176 - 41 = 135
