A = 3 + 2 + 2 ^ 2 + 2 ^ 3 + ... + 2 ^ 50
2A = 6 + 2 ^ 2 + 2 ^ 3 + 2 ^ 4 + ... + 2 ^ 51
2A - A = ( 6 + 2 ^ 2 + 2 ^ 3 + 2 ^ 4 + ... + 2 ^ 51 )
- ( 3 + 2 + 2 ^ 2 + 2 ^ 3 + ... + 2 ^ 50 )
A = 6 + 5 ^ 51 - 3 - 2
A = 5 ^ 51 + 1
a, 50 - [ ( 20 - 2^3 ) : 2 + 34 ] b, 50 - [ ( 50 - 2^3 . 5 ) : 2 +3 ] LÀM ƠN GIÚP MÌNH
Tính
a, 2^2+4^2+6^2+...........+50^2
b, 1^3+2^3+3^3+............+50^3
A=3+2+2^2+2^3+.....+2^50
tính các tổng sau
A=1*2+2*3+3*4+4*5+5*6+6*7...+49*50
B=1*50+2*49+3*48+...+49*2+50*1
A= 2+2^2+2^3+...+2^19+2^20
b=2+2^3+2^5+...2^97+2^99
C=5+5^2+5^3+...+5^50
D=1+3+3^2+3^3+...+3^100
a , CM A = 1/1^2+1/2^2+......+1/50^2 < 2
b, Tinhs B = 3+3/2+3/2^2 +...+3/2^9
Rút gọn:
a, C=1+3+3^2+3^3+.....................................+3^20
b, B=2+2^2+2^3+.........................................+2^49+2^50
a. 1! + 2 . 2! + 3 . 3! + ... + 10 . 10!
b. 1 . 2 + 2. 5 + 3 . 8 + ... + 50 . 149
c. 1 . 4 + 2 . 5 + 3 . 6 + .. + 50 . 53
d. \(\frac{3}{2^2}.\frac{8}{3^2}.\frac{15}{4^2}.....\frac{899}{30^2}\)
Các bạn giúp mk nhóa!
Tinh :
a) 1.2+2.3 + .... + 49 . 50
b) 1 mũ 2 + 2 mũ 2 + ....+ 50 mũ 2
c) 1 .2 .3 + 2 .3 .4 + ..... + 98 .99 .100