\(C=3+2.3+2^2.3+2^3.3+...+2^{10}.3\)
\(=3\left(1+2+2^2+...+2^{10}\right)\)
\(\Rightarrow2C=3\left(2+2^2+...+2^{10}+2^{11}\right)\)
\(\Rightarrow2C-C=3\left(2^{11}-1\right)\)
\(\Rightarrow C=3\left(2^{11}-1\right)=6141\)
Tính:\(S=3-3+6-9+12+24-27+48-81+...-2187+3072+6144-6561+12288\)
a. 1 + 6 + 11 + 16 + ... + 46 + 51
b. 2 + 5 + 11 + ... + 47 + 65
c. 3 + 12 + 48 + ... + 3072 + 12228
d. 2 + 5 + 7 + 12 + ... + 81 + 131
3+12+48+..+3072+12288
3 + 12 + 48 + ....... 3072 + 12288
2 + 5 + 7 + 12 + ........81 + 131
tính hợp lí
3+12+48+.....+3072+12288
tính nhanh
a, 2+5+11+...........+47+65
b, 1+6+11+16+......+46+51
c, 3+12+48+.......+3072+12288
d, 49-51+53-55+57-59+61-63+65
a.2+5+11+...+47+65
B.3+12+48+...+3072+12288
Tinh:
a)1+2+3+.....+98+99+100
b)2+4+6+......+998+1000
c)1+6+11+....+47+65
d)2+5+11+.....+47+65
e)3+12+48+.....+3072+12288
giúp mình nha!!!!!ai có hình Naruto hoặc Kurama thì kb nha!!!!!
1 + 2 + 3...... + 98 + 99 + 100
2 + 4 + 6...... + 98 + 1000
1 + 6 + 11 + 16 + .......45 + 51
2 + 5 + 11 + ....... + 47 + 65
3 + 12 + 48 + ....... 3072 + 12288
2 + 5 + 7 + 12 + ........81 + 131
giúp mình với nha !!! mk nộp gấp r