1/2+1+11/2+2+21/2+…+491/2+50.

问题描述:

1
2
+1+1
1
2
+2+2
1
2
+…+49
1
2
+50.

1
2
+1+1
1
2
+2
1
2
+…+49
1
2
+50,
=(1+2+…+50)×2-50+
1
2
×50,
=(1+50)×50÷2×2-50+25,
=2550-50+25,
=2525.