a) \(8\left(x-2\right)=3\)
\(\Leftrightarrow x-2=\dfrac{3}{8}\)
\(\Leftrightarrow x=\dfrac{3}{8}+2\)
\(\Leftrightarrow x=\dfrac{19}{8}\)
Vậy \(x=\dfrac{19}{8}\)
b) \(9^{x+1}-5.3^{2x}=324\)
\(\Rightarrow9^x.9-\left(3^2\right)^x.5=324\)
\(\Rightarrow9^x.9-9^x.5=324\)
\(\Rightarrow9^x\left(9-5\right)=324\)
\(\Rightarrow9^x.4=324\)
\(\Rightarrow9^x=\dfrac{324}{4}\)
\(\Rightarrow9^x=81\)
\(\Rightarrow9^x=9^2\)
\(\Rightarrow x=2\)
Vậy \(x=2\)
a, \(8\left(x-2\right)=3\)
\(\Rightarrow x-2=\dfrac{3}{8}\Rightarrow x=\dfrac{19}{8}\)
b, \(9^{x+1}-5.3^{2x}=324\)
\(\Rightarrow9^x.9-5.9^x=324\)
\(\Rightarrow4.9^x=324\Rightarrow9^x=81=9^2\)
Vì \(9\ne\pm1;9\ne0\) nên \(x=2\)
Chúc bạn học tốt!!!
a) 8.(x-2)=3.
=> (x-2)= 3:8 = 0.375.
x = 0.375 + 2 = 2.375.
b) 9x+1 - 5.32x = 324.
<=> 9.9x - 5.32x=324.
<=> 9.32x - 5.32x=324.
<=> 32x.(9-5)= 32x.4= 324.
<=> 32x=324:4=81=34.
<=>2x = 4.
<=> x= 2.
