Question

[༻𝓝𝒽𝓸༺]

  giúp mình với ạ mình đang cần gấp 

Answer 1

[⭐Hannie⭐]

Cậu tách ra vài câu một lượt thoii ạa

Answer 2

[HT.Phong (9A5)]

Bài 5:

a) \(x:\left(-\dfrac{1}{2}\right)^3=-\dfrac{1}{2}\)

\(\Rightarrow x=\left(-\dfrac{1}{2}\right)^3\cdot\left(-\dfrac{1}{2}\right)\)

\(\Rightarrow x=\left(\dfrac{1}{2}\right)^4=\dfrac{1}{16}\)

b) \(\left(\dfrac{3}{4}\right)^5\cdot x=\left(\dfrac{3}{4}\right)^7\)

\(\Rightarrow x=\left(\dfrac{3}{4}\right)^7:\left(\dfrac{3}{4}\right)^5\)

\(\Rightarrow x=\left(\dfrac{3}{4}\right)^2=\dfrac{9}{16}\)

c) \(\left(\dfrac{2}{3}\right)^5:x=\left(\dfrac{2}{3}\right)^3\)

\(\Rightarrow x=\left(\dfrac{2}{5}\right)^5:\left(\dfrac{2}{3}\right)^3\)

\(\Rightarrow x=\left(\dfrac{2}{5}\right)^2=\dfrac{4}{25}\)

d) \(\dfrac{25}{5^x}=5\)

\(\Rightarrow5^x\cdot5=25\)

\(\Rightarrow5^{x+1}=25\)

\(\Rightarrow5^{x+1}=5^2\)

\(\Rightarrow x+1=2\)

\(\Rightarrow x=2-1=1\)

e) \(\left(-\dfrac{1}{3}\right)^{x-5}=\dfrac{1}{81}\)

\(\Rightarrow\left(-\dfrac{1}{3}\right)^{x-5}=\left(-\dfrac{1}{3}\right)^4\)

\(\Rightarrow x-5=4\)

\(\Rightarrow x=4+5=9\)

g) \(\left(2x-3\right)^2=9\)

\(\Rightarrow\left(2x-3\right)=3^2\)

\(\Rightarrow2x-3=3\)

\(\Rightarrow2x=6\)

\(\Rightarrow x=\dfrac{6}{2}=3\)

h) \(\left(x+5\right)^3=64\)

\(\Rightarrow\left(x+5\right)^3=4^3\)

\(\Rightarrow x+5=4\)

\(\Rightarrow x=4-5=-1\)

i) \(2^{3x+2}=4^{x+5}\)

\(\Rightarrow2^{3x+2}=\left(2^2\right)^{x+5}\)

\(\Rightarrow2^{3x+2}=2^{2x+10}\)

\(\Rightarrow3x+2=2x+10\)

\(\Rightarrow3x-2x=10-2\)

\(\Rightarrow x=8\)

k) \(5^{x+1}-5^x=500\)

\(\Rightarrow\left(5-1\right)\cdot5^x=500\)

\(\Rightarrow4\cdot5^x=500\)

\(\Rightarrow5^x=125\)

\(\Rightarrow5^x=5^3\)

\(\Rightarrow x=3\)