Find the values of x in each of the following:
(i) $2^{5 x} \div 2 x=\sqrt[5]{2^{20}}$
(ii) $\left(2^{3}\right)^{4}=\left(2^{2}\right)^{x}$
(iii) $\left(\frac{3}{5}\right)^{x}\left(\frac{5}{3}\right)^{2 x}=\frac{125}{27}$
(iv) $5^{x-2} \times 3^{2 x-3}=135$
(v) $2^{x-7} \times 5^{x-4}=1250$
(vi) $(\sqrt[3]{4})^{2 x+\frac{1}{2}}=\frac{1}{32}$
(vii) $5^{2 x+3}=1$
(viii) $(13)^{\sqrt{x}}=4^{4}-3^{4}-6$
(ix) $\left(\sqrt{\frac{3}{5}}\right)^{x+1}=\frac{125}{27}$
From the following we have to find the value of x
(i) Given $2^{5 x} \div 2^{x}=\sqrt[5]{2^{20}}$
By using rational exponents $\frac{a^{m}}{a^{n}}=a^{m-n}$
$2^{5 x-x}=2^{20 \times \frac{1}{5}}$
On equating the exponents we get,
$5 x-x=4$
$4 x=4$
$x=\frac{4}{4}$
$x=1$
The value of $x$ is 1
(ii) Given $\left(2^{3}\right)^{4}=\left(2^{2}\right)^{x}$
$\begin{aligned} 2^{3 \times 4} &=2^{2 \times x} \\ 2^{12} &=2^{2 x} \end{aligned}$
On equating the exponents
$\begin{aligned} 12 &=2 x \\ \frac{12}{2} &=x \\ 6 &=x \end{aligned}$
Hence the value of $x$ is 6
(iii) Given $\left(\frac{3}{5}\right)^{x}\left(\frac{5}{3}\right)^{2 x}=\frac{125}{27}$
Comparing exponents we have,
$2 x-x=3$
$1 x=3$
$x=\frac{3}{1}$
$x=3$
Hence the value of x is
(iv) Given $5^{x-2} \times 3^{2 x-3}=135$
$5^{x-2} \times 3^{2 x-3}=5 \times 3^{3}$
On equating the exponents of 5 and 3 we get,
$x-2=1$
$x=3$
And,
$2 x-3=3$
$2 x=6$
$x=\frac{6}{2}$
$x=3$
The value of x is
(v) Given $2^{x-7} \times 5^{x-4}=1250$
$2^{x-7} \times 5^{x-4}=2^{1} \times 625$
$2^{x-7} \times 5^{x-4}=2^{1} \times 5^{4}$
On equating the exponents we get
$x-7=1$
$x=1+7$
$x=8$
And,
$x-4=4$
$x=4+4$
$x=8$
Hence the value of x is
(vi) $(\sqrt[3]{4})^{2 x+\frac{1}{2}}=\frac{1}{32}$
$\left(2^{2}\right)^{\frac{1}{3}\left(\frac{4 x+1}{2}\right)}=\left(\frac{1}{2}\right)^{5}$
$\Rightarrow 2^{\left(\frac{4 x+1}{3}\right)}=2^{-5}$
On comparing we get,
$\frac{4 x+1}{3}=-5$
$\Rightarrow 4 x+1=-15$
$\Rightarrow 4 x=-16$
$\Rightarrow x=-4$
(vii) $5^{2 x+3}=1$
$5^{2 x+3}=5^{0}$
$\Rightarrow 2 x+3=0$
$\Rightarrow x=\frac{-3}{2}$
(viii) $(13)^{\sqrt{x}}=4^{4}-3^{4}-6$
$(13)^{\sqrt{x}}=\left(2^{2}\right)^{4}-3^{4}-6$
$\Rightarrow(13)^{\sqrt{x}}=2^{8}-3^{4}-6$
$\Rightarrow(13)^{\sqrt{x}}=256-81-6$
$\Rightarrow(13)^{\sqrt{x}}=169$
$\Rightarrow(13)^{\sqrt{x}}=(13)^{2}$
On comparing we get,
$\sqrt{x}=2$
on squaring both sides we get,
$\mathrm{x}=4$
(ix) $\left(\sqrt{\frac{3}{5}}\right)^{x+1}=\frac{125}{27}$
$\left(\sqrt{\frac{3}{5}}\right)^{x+1}=\left(\frac{5}{3}\right)^{3}$
$\Rightarrow\left(\frac{3}{5}\right)^{\frac{x+1}{2}}=\left(\frac{3}{5}\right)^{-3}$
On comparing we get,
$\frac{x+1}{2}=-3$
$\Rightarrow x+1=-6$
$\Rightarrow x=-7$