1.1*1.2*1.3*y =2.3*2.2*2.1*y

tim y

Tính nhanh

A)A=1.2+2.3+3.4+....+98.3+99.2+100.1

B)B=1.100+2.99+3.98+...+98.3+99.2+100.1

Tính nhanh 

A=1.2+2.3+3.4+...+1999.2000

B=1.1+2.2+3.3+...+1999.1999

C=1.2.3+2.3.4+...+48.48.50

D=1.3+3.5+5.7+...+97.99

B=1.3^0+2.3^1+3.3^2+...+99.3^18.Tim B.

1.2 * 1.3 * 1.4* y = 2.2 * 2.3 * 2.4 *y

^y=

Find the value of y such that:

1.1 x 1.2 x 1.3 x y= y x 2.1 x 2.2 x 2.3

Tính nhanh 1.100+2.99+3.98+...+98.3+99.2+100.1/1.2+2.3+3.4+...+99.100

Thu gọn tổng sau:

S = 1.2^2+2.2^3+3.2^4+...+99.2^100

tính A=\(1.2+2.2^2+3.2^3+...+99.2^{99}+100.2^{100}\)