\(4^{19}=2^{2.19}=2^{38}\)

\(8^7=2^{3.7}=2^{21}\)

\(256^4=2^{8.4}=2^{32}\)

\(32^3=2^{5.3}=2^{15}\)

\(\Rightarrow E=\frac{2^{38}+2^{21}}{2^{32}+2^{15}}=\frac{2^{21}.\left(2^{17}+1\right)}{2^{15}.\left(2^{17}+1\right)}=\frac{2^{21}}{2^{15}}=2^6=64\)

\(\frac{4^{19}+8^7}{256^4+32^2}=\frac{\left(2^2\right)^{19}+\left(2^3\right)^7}{\left(2^8\right)^4+\left(2^5\right)^2}=\frac{2^{38}+2^{21}}{2^{32}+2^{10}}=\frac{2^{21}.\left(2^{17}+1\right)}{2^{10}.\left(2^{22}+1\right)}=\frac{2^{11}.\left(2^{17}+1\right)}{2^{22}+1}=\frac{2^{28}+2^{11}}{2^{22}+1}\)

a)=18-5-7

=13-7

=5

b)=(48-2)+(-21)

46+(-21)

=25

c)=-200.(-2)+20

=400+20=420

Đặt A=7/2+7/4+...+7/256

=>2A=7+7/2+...+7/128

=>A=7-7/256=7*255/256=1785/256

1/ 2 + 2 = 4

2/ 4 + 4 = 8

3/ 8 + 8 = 16

4/ 16 + 16 = 32

5/ 32 + 32 =64

6/ 64 + 64 =128

7/ 128 + 128 =256

8/  256 + 256 =512

9/ 521 + 512 =1033

10/ 2048 + 2048 =4096

k mình đi

4

8

16

32

64

128

256

512

2048

4096