\(\frac{x}{2}-\frac{11}{5}=\frac{7}{5}.\frac{64}{49}\)

\(\frac{x}{2}-\frac{11}{5}=\frac{64}{35}\)

\(\frac{x}{2}=\frac{64}{35}+\frac{11}{5}\)

\(\frac{x}{2}=\frac{141}{35}\)

\(\Leftrightarrow x.35=2.141\)

\(\Leftrightarrow x.35=282\)

\(\Leftrightarrow x=282:35\)

\(\Leftrightarrow x=\frac{282}{35}\)

x/2 - 11/5 = 7/5.64/49

=> x/2 - 11/5 = 64/35

=> x/2 = 64/35 + 11/5

=> x/2 = 141/35

=> 35x = 2.141

=> 35x = 282

=> x = 282 : 35 = 282/35

a) (2+1)(2^2+1)(2^4+1)...(2^32+1)-2^64

=(2+1)(2-1)(2^2+1)(2^4+1)...(2^32+1)-2^64

=(2^2-1)(2^2+1)(2^4+1)...(2^32+1)-2^64

=(2^4-1)(2^4+1)....(2^32+1)-2^64

=......

=(2^32-1)(2^32+1)-2^64

=2^64-1-2^64=-1

b)Đặt A=(5+3)(5^2+3^2)(5^4+3^4)...(5^64+3^64)+(5^128-3^128)/2

đặt B=(5+3)(5^2+3^2)(5^4+3^4)...(5^64+3^64)

\(2B=\left(5-3\right)\left(5+3\right)\left(5^2+3^2\right)\left(5^4+3^4\right)...\left(5^{64}+3^{64}\right)\)

\(2B=\left(5^2-3^2\right)\left(5^2+3^2\right)\left(5^4+3^4\right)...\left(5^{64}+3^{64}\right)\)

\(2B=\left(5^4-3^4\right)\left(5^4+3^4\right)...\left(5^{64}+3^{64}\right)\)

\(2B=.......\)

2B=(5^64-3^64)(5^64+3^64)

2B=5^128-3^128

B=(5^128-3^128)/2 (thế vào đề bài)

=> A=B+(5^128-3^128)/2=(5^128-3^128)/2+(5^128-3^128)/2=\(\frac{2\left(5^{128}-3^{128}\right)}{2}=\left(5^{128}-3^{128}\right)\)

a) A = ( 2-1)(2+1)(2²+1)...(2³²+1)-2⁶⁴

         =(2²-1)(2²+1)(2⁴+1)... -2⁶⁴

       =....

       =2⁶⁴-1-2⁶⁴=1

câu b tương tự nhá

khó qua mik mới hc lớp 7 thôi

\(\left(\frac{3}{5}-\frac{2}{3}x\right)^3=\left(\frac{-4}{5}\right)^3\)

\(\frac{3}{5}-\frac{2}{3}x=\frac{-4}{5}\)

\(\frac{2}{3}x=\frac{7}{5}\)

\(x=\frac{21}{10}\)

\(\left(\frac{3}{5}-\frac{2}{3}.x\right)^3=\frac{-64}{125}\)

\(\Leftrightarrow\left(\frac{3}{5}-\frac{2}{3}.x\right)^3=\left(-\frac{4}{5}\right)^3\)

\(\Rightarrow\frac{3}{5}-\frac{2}{3}.x=-\frac{4}{5}\)

\(\Leftrightarrow\frac{2}{3}.x=\frac{3}{5}-\left(-\frac{4}{5}\right)\)

\(\Leftrightarrow\frac{2}{3}.x=\frac{3}{5}+\frac{4}{5}\)

\(\Leftrightarrow\frac{2}{3}.x=\frac{7}{5}\)

\(\Leftrightarrow x=\frac{7}{5}:\frac{2}{3}\)

\(\Leftrightarrow x=\frac{21}{10}\)

Vậy \(x=\frac{21}{10}\)

\(\left(\frac{3}{5}-\frac{2}{3}x\right)^3=\frac{-64}{125}\)

\(\left(\frac{3}{5}-\frac{2}{3}x\right)^3=\left(\frac{-4}{5}\right)^3\)

\(\frac{3}{5}-\frac{2}{3}x=\frac{-4}{5}\)

\(\frac{9}{15}-\frac{10x}{15}=\frac{-12}{15}\)

\(-\frac{10x}{15}=\frac{9}{15}-\frac{-12}{15}\)
\(\text{ }-10x=9+12\)

\(-10x=21\)

\(x=\frac{-21}{10}\)

k nha

\(\left(-64\right)\cdot125=x^3\)

\(\Rightarrow-8000=x^3\)

\(\Rightarrow\left(-20\right)^3=x^3\)

\(\Rightarrow x=-20\)

Khi đó :

-5 . x_o = -5 . ( -20 ) = 100

\(\left(x+2\right)^5-\left(x-2\right)^5=64\)

\(\Rightarrow x^5+10x^4+40x^3+80x^2+80x+32-\left(x^5-10x^4+40x^3-80x^2+80x-32\right)=64\)

\(\Rightarrow20x^4+160x^2+64=64\)

\(\Rightarrow20x^4+160x^2=0\)

\(\Rightarrow20x^2\left(x^2+8\right)=0\)

mà \(x^2+8>0\)

\(\Rightarrow x^2=0\Rightarrow x=0\)

\(\Leftrightarrow x^5+10x^4+40x^3+80x^2+80x+32-x^5+10x^4-40x^3+80x^2-80x+32=64\)

\(\Rightarrow20x^4+160x^2+54-64=0\)

\(\Rightarrow20x^4+160x^2=0\)

\(\Leftrightarrow20x^2\left(x^2+8\right)=0\)

\(\Leftrightarrow x=0\)

Do \(x^2+8=\ge0\)(luôn đúng)

Vây: \(x^2\ge-8\)

a, (\(\frac{1}{2}\))^x = \(\frac{1}{64}\)

<=> (\(\frac{1}{2}\))^x = (\(\frac{1}{2}\))⁶

<=> x = 6

b, 3⁵ :3^x = 9

<=> 3⁵ :3^x = 3² 

<=> 3^x = 3⁵ :3²

<=> 3^x = 3³

<=> x = 3

Chúc bạn học tốt

a,\(\left(\frac{1}{2}\right)^x=\frac{1}{64}\)

\(\left(\frac{1}{2}\right)^x=\left(\frac{1}{2}\right)^6\)

\(\Rightarrow x=6\)

b,\(3^5:3^x=9\)

\(3^5:3^x=3^2\)

\(3^x=3^5:3^2\)

\(3^x=3^3\)

\(\Rightarrow x=3\)

\(a,\left(\frac{1}{2}\right)^x=\frac{1}{64}\)

\(\Rightarrow\left(\frac{1}{2}\right)^x=\left(\frac{1}{2}\right)^6\)

\(\Rightarrow x=6\)

Vậy...

\(b,3^5:3^x=9\)

\(\Rightarrow3^5:3^x=3^2\)

\(\Rightarrow3^x=3^3\)

\(\Rightarrow x=3\)

Vậy...

\(78-\left(x-25\right).3\frac{1}{3}=73\)

\(78-\left(x-25\right)\cdot\frac{10}{3}=73\)

\(\left(x-25\right)\cdot\frac{10}{3}=78-73\)

\(\left(x-25\right)\cdot\frac{10}{3}=5\)

\(x-25=5:\frac{10}{3}\)

\(x-25=1,5\)

\(x=25+1,5=26,5\)

19x64+76x34

=(19x4)x16+76x34

=76x(16+34)

=76x50

=3800

a) 19 x 64 + 76 x 34

= 19 x 64 + 19 x 4 x 34

= 19 x ( 64 + 4 x 34 )

= 19 x 200

= 3800

k cho mình rùi mình giải bài b) cho