Răspuns :
S=4+6+8+...+200 /2
S/2=(1+2+3+...+100)-1
S/2=100*101/2-1
S/2=10100/2-1
S/2=5050-1
S/2=5049
S=5049*2
S=10098
S/2=(1+2+3+...+100)-1
S/2=100*101/2-1
S/2=10100/2-1
S/2=5050-1
S/2=5049
S=5049*2
S=10098