E= 1.2.2+ 2.3.3+ 3.4.4+......+ 49.50.50
E= 1.2.2+2.3.3+3.4.4+.......+ 49.50.50
A= 1.1 + 2.2 +3.3 + 4.4 + ... +20.20
B= 1.2.2 + 2.3.3 + 3.4.4 + 19.20.20
C= 1.2 +3.4 + 5.6 + ... + 19.20
Nhờ các bạn giải giúp mình các bạn toán sau:
A = 1.2 + 3.4 + 5 .6 + ... + 49.50
B = 1.1 + 2.2 + 3.3 + ... + 49.49
C = 2.2 + 4.4 + 6.6 + ... + 48.48
D = 1.2.2 + 2.3.3 + ... + 49.50.50
E = 1.2.3 + 2.3.4 + ... + 48.49.50
B = 49.(49 + 1).(2 . 49 + 1) / 6 = 40425
C = 4.(12 + 22 + … + 242 ) = 4.24.(24 + 1)(2.24 + 1) / 6 = 19600
A= 1^2/1.2.2^2/2.3.3^2/3.4.4^2/4.5.5^2/5.6
B= 2^2/1.3.3^2/2.4.4^2/3.5.5^2/4.6
Giup minh nhe minh tick cho
A=12/1.2 . 22/2.3 . 32/3.4 . 42/4.5 . 52/5.6
⇒1.1/1.2 . 2.2/2.3 . 3.3/3.4 . 4.4/4.5 . 5.5/5.6
⇒1.2.3.4.5/1.2.3.4.5 . 1.2.3.4.5/2.3.4.5.6
⇒1 . 1/6 =1/6.
Vậy A=1/6
B=22/1.3 . 32/2.4 . 42/3.5 . 52/4.6
⇒2.2/1.3 . 3.3/2.4 . 4.4/3.5 . 5.5/4.6
⇒2.2.3.3.4.4.5.5/1.3.2.4.3.5.4.6 =48.
Vậy B=48.
12/1.2.22/2.3.32/3.4.......9992999.1000
12/1.2.22/2.3.32/3.4.52/5.6.62/6.7.72.7.8.82/8.9.92/9.10
1.2.2
A=1.2.3+2.3.3+3.4.3+4.5.3+...+98.99.3
A=1.2.3+2.3.4-1.2.3+3.4.5-2.3.4+...+98.99.100-97.98.99
A=98.99.100
A=970200 nha bạn
tinh A( 10.11+11.12+...+50.51)-(1.2.3+2.3.3+...+19.20.21)-5-10-15-...-95