\(A=\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+\frac{1}{16}+\frac{1}{32}+\frac{1}{64}+\frac{1}{128}\)

\(2\times A=1+\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+\frac{1}{16}+\frac{1}{32}+\frac{1}{64}\)

\(2\times A-A=\left(1+\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+\frac{1}{16}+\frac{1}{32}+\frac{1}{64}\right)-\left(\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+\frac{1}{16}+\frac{1}{32}+\frac{1}{64}+\frac{1}{128}\right)\)

\(A=1-\frac{1}{128}\)

\(A=\frac{127}{128}\)

\(B=\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+\frac{1}{16}\)

\(2\times B=1+\frac{1}{2}+\frac{1}{4}+\frac{1}{8}\)

\(B=1-\frac{1}{16}=\frac{15}{16}\)

\(\left(x+\frac{1}{2}\right)+\left(x+\frac{1}{4}\right)+\left(x+\frac{1}{8}\right)+\left(x+\frac{1}{16}\right)=1\)

\(\Leftrightarrow4\times x+\frac{15}{16}=1\)

\(\Leftrightarrow4\times x=\frac{1}{16}\)

\(\Leftrightarrow x=\frac{1}{64}\)

??????????

khong bit

x . 4 + 15/16 = 1

x . 4 = 1 – 15/16 = 1/16

x = 1/16 : 4 = 1/64

\(\left(x+\frac{1}{2}\right)+\left(x+\frac{1}{4}\right)+\left(x+\frac{1}{8}\right)+\left(x+\frac{1}{16}\right)\)

\(=4x+\left(\frac{8}{16}+\frac{4}{16}+\frac{2}{16}+\frac{1}{16}\right)\)

\(=4x+\frac{15}{16}\)

1/8*16^x=2^x

1/8=2^x/16^x

(2/16)^x=1/8

(1/8)^x=1/8

suy ra x=1

Vậy x=1

\(\frac{1}{8}\cdot16^x=2^x\)

\(\Leftrightarrow\frac{1}{8}=\frac{2^x}{16^x}\)

\(\Leftrightarrow\left(\frac{2}{16}\right)^x=\frac{1}{8}\)

\(\Leftrightarrow\left(\frac{1}{8}\right)^x=\frac{1}{8}\)

Suy ra x=1

(x-2)=1/2X16

(x-2)=8

x=10

Tim x:

a,-16+23+x=-16

x=-16+16+23

x=23

b,(x-1)-(-2)=0

x-1+2=0

x+1=0

x=-1

c,|x-1|=0

x-1=0

x=1

d,|9-x|=64+(-7)

\(|9-x|=57\)

\(\orbr{\begin{cases}9-x=57\\9-x=-57\end{cases}}\)

\(\orbr{\begin{cases}x=-48\\x=66\end{cases}}\)

a,-16+23+x=-16

23+x=0

x=-32

b,(x-1)-(-2)=0

(x-1)+2=0

x-1=-2

x=-1