\(\dfrac{\left(2^8-2^6\right)^3}{64^4}=\dfrac{27}{64}\)

\(\dfrac{192^3}{64^4}=\dfrac{27}{64}\)

\(\dfrac{\left(3\times64\right)^3}{64^3\times64}=\dfrac{27}{64}\)

\(\dfrac{3^3\times64^3}{64\times64^3}=\dfrac{27}{64}\)

\(\dfrac{3^3}{64}=\dfrac{27}{64}\)

\(\dfrac{27}{64}=\dfrac{27}{64}\)

a) \(\left(-\frac{3}{4}\right)^{3x-1}=\frac{-27}{64}\)

\(\Leftrightarrow\left(-\frac{3}{4}\right)^{3x-1}=\left(-\frac{3}{4}\right)^3\)

\(\Leftrightarrow3x-1=3\)

\(\Leftrightarrow3x=4\)

\(\Leftrightarrow x=\frac{4}{3}\)

b) Đề sai ! Sửa :

\(\left(\frac{4}{5}\right)^{2x+5}=\frac{256}{625}\)

\(\Leftrightarrow\left(\frac{4}{5}\right)^{2x+5}=\left(\frac{4}{5}\right)^4\)

\(\Leftrightarrow2x+5=4\)

\(\Leftrightarrow2x=-1\)

\(\Leftrightarrow x=-\frac{1}{2}\)

c) \(\frac{\left(x+3\right)^5}{\left(x+5\right)^2}=\frac{64}{27}\)

\(\Leftrightarrow\left(x+3\right)^3=\left(\frac{4}{3}\right)^3\)

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

\(\Leftrightarrow x=-\frac{5}{3}\)

d) \(\left(x-\frac{2}{15}\right)^3=\frac{8}{125}\)

\(\Leftrightarrow\left(x-\frac{2}{15}\right)^3=\left(\frac{2}{15}\right)^3\)

\(\Leftrightarrow x-\frac{2}{15}=\frac{2}{15}\)

\(\Leftrightarrow x=\frac{4}{15}\)

A/   \(\left(15-6\frac{13}{18}\right):11\frac{1}{27}-2\frac{1}{8}:1\frac{11}{40}\)

\(=\left(15-\frac{121}{18}\right):\frac{298}{27}-\frac{17}{8}:\frac{51}{40}\)

\(=\left(\frac{270}{18}-\frac{121}{18}\right):\frac{298}{27}-\frac{17}{8}:\frac{51}{40}\)

\(=\frac{149}{18}:\frac{298}{27}-\frac{17}{8}:\frac{51}{40}\)

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

\(=\frac{9}{12}-\frac{20}{12}\)\(=-\frac{11}{12}\)

B/  \(\left(-3,2\right)\cdot-\frac{15}{64}+\left(0,8-2\frac{4}{15}\right):3\frac{2}{3}\)

\(=\left(-3,2\right)\cdot-\frac{15}{64}+\left(0,8-\frac{34}{15}\right):\frac{11}{3}\)

\(=-\frac{3,2}{1}\cdot-\frac{15}{64}+\left(0,8-\frac{34}{15}\right):\frac{11}{3}\)

\(=\frac{48}{64}+\left(0,8-\frac{34}{15}\right):\frac{11}{3}\)

\(=\frac{3}{4}+\left(\frac{12}{15}-\frac{34}{15}\right):\frac{11}{3}\)

\(=\frac{3}{4}+\left(-\frac{22}{15}\right):\frac{11}{3}\)

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

\(=\frac{15}{20}+\left(-\frac{8}{20}\right)\)

\(=\frac{7}{20}\)

\(\sqrt{64}+3.\sqrt{\left(\frac{1}{2}\right)^0}-\frac{\sqrt{16}}{4}+\left(\sqrt{\left(-4\right)^2:\frac{1}{2}}\right).8\)

= \(8+3.1-\frac{4}{4}+\left(\sqrt{16:\frac{1}{2}}\right).8\) 

=\(8+3-1+\left(\sqrt{16.2}\right).8\)

=\(8+3-1+\left(\sqrt{32}\right).8\)

=\(11-1+\left(\sqrt{32}\right).8\)

= \(10+5,65685424949.8\)

= \(10+45,2548339959\)

=\(55,2548339959\)

Mình ko biết là có đúng không í

vì mình thấy đề bài có gì sai ý!!!

\(\sqrt{64}+3\sqrt{\left(\frac{1}{2}\right)^0}-\frac{\sqrt{16}}{4}+\left(\sqrt{\left(-4\right)^2}:\frac{1}{2}\right).8\)

\(=\sqrt{8^2}+3\sqrt{1}-\frac{\sqrt{4^2}}{4}+\left(\sqrt{16}:\frac{1}{2}\right).8\)

\(=8+3-\frac{4}{4}+\left(\sqrt{4^2}:\frac{1}{2}\right).8\)

\(=11-1+\left(4.2\right).8\)

\(=10+8.8=10+64=74\)

cái này bấm máy tính casio hoặc deli.... là ra ngay hoi !!!

\(\sqrt{8}+3.\sqrt{\left(\frac{1}{2}\right)^0}-\frac{\sqrt{16}}{4}+\left(\sqrt{\left(-4\right)^2}:\frac{1}{2}\right).8\)

\(=8+3-\frac{4}{4}+\left(4:\frac{1}{2}\right).8\)

\(=10+8.8\)

\(=74\)

Ta có : 3^x + 3^{x + 2} = 810

=> 3^x(1 + 3²) = 810

=> 3^x.10 = 810

=> 3^x = 81

=> 3^x = 3⁴

=> x = 4

ta có \(3^3+3^x+2=810\)

=>\(3^x\left(1+3^2\right)=810\)

=>\(3^x.10=810\)

=>\(3^x=81\)

=>\(3^x=3^4\)

=>x=4

Vậy x=4

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A = \(\frac{1}{2}-\frac{3}{4}+\frac{5}{6}-\frac{7}{12}\)

A = \(\left(-\frac{1}{4}\right)+\frac{5}{6}-\frac{7}{12}\)

A = \(\frac{7}{12}-\frac{7}{12}\)

A = \(0\).

Mình làm câu A thôi nhé.

Chúc bạn học tốt!

KQ là \(-\frac{61}{16}\)

mk ko bít bạn có cần lời giải ko mk chỉ vít kq hoi 

có j nếu cần lời giải ns mk ha  

\(4\frac{25}{16_{ }}+25.\left(\frac{9}{16}-\frac{117}{64}\right):\frac{27}{8}\)

=\(\frac{25}{4}+25.\left(\frac{36}{64}-\frac{117}{64}\right):\frac{27}{8}\)

=\(\frac{25}{4}+25.\left(\frac{-81}{64}\right):\frac{28}{7}\)

=\(\frac{25}{4}+\left(\frac{-2025}{64}\right).\frac{7}{28}\)

=\(\frac{25}{4}+\left(\frac{-2025}{256}\right)\)

=\(\frac{1600}{256}-\frac{2025}{256}\)

=\(\frac{-425}{256}\)

bn xem có đúng k  nhé!