Semisuma inseamna jumatate din suma, adica (a+b+c+d) : 2
Nr pare consecutive fiecare e cu 2 mai mare decat celalalt, adica 22 ,24,26 etc.
Problema ta :
a+b+c+d= 290 x 2 =580
b=a+2
c=a+4
d=a+6
a+a+2+a+4+a+6=580
4a +12 =580
4a = 580 -12
4a = 568
a= 568 : 4 = 142
nr.142, 144, 146, 148
