\(=\dfrac{\left(105+3\right)\left[\left(105-3\right):2+1\right]}{2}=\dfrac{108\cdot52}{2}=2808\)
Đúng 0
Bình luận (0)
\(=\dfrac{\left(105+3\right)\left[\left(105-3\right):2+1\right]}{2}=\dfrac{108\cdot52}{2}=2808\)
tinh tong:1/1*3*5+1/3*5*7+......+1/101*103*105
tinh tong:1/1*3*5+1/3*5*7+......+1/101*103*105
1 - 3 + 5 - 7 +...+ 101 - 103 + 105
Cách làm luôn nha!!!!!
1+2-3-4+5+6-7-8+9+.......+101+102-103-104+105
1-2-3+4+5-6-7+8+..+100+101-102-103+104+105
CMR:1+2-3-4+5+6-7-8+...+101+102-103-104+105=1
Tính:
1-2-3+4+5-6-7+8+.....+101-102-103+104+105
Tính nhanh :
a) 1-2-3+4+5-6-7+8+9-10-.......+200+201-202-203
b) -1+3-5+7-9+11-...........-101+103-105+107-109
Tính nhanh (nếu có thể):
a) 2154 - 42 - 2155 + 2
b) -(27-85) - (73+15)
c) 1 +2 -3 -4 +5 +6 -7 -8 +9 +...+101 +102 -103 -104 +105