a,
$\dfrac{3}{5}-x=\dfrac{1}{3}$
$x=\dfrac{3}{5}-\dfrac{1}{3}$
$x=\dfrac{4}{15}$
Vậy $x=\dfrac{4}{15}$
b,
$\dfrac{-2}{15}-x=\dfrac{-3}{10}$
$x=\dfrac{-2}{15}-\dfrac{-3}{10}$
$x=\dfrac{1}{6}$
Vậy $x=\dfrac{1}{6}$
c,
$\dfrac{3}{2}x-\dfrac{2}{5}=\dfrac{1}{3}x-\dfrac{1}{4}$
$\dfrac{3}{2}x-\dfrac{2}{5}-\dfrac{1}{3}x+\dfrac{1}{4}=0$
$\dfrac{7}{6}x-\dfrac{3}{20}=0$
$\dfrac{7}{6}x=\dfrac{3}{20}$
$x=\dfrac{9}{70}$
Vậy $x=\dfrac{9}{70}$
d,
$2^x=8^9$
$2^x=(2^3)^9$
$2^x=27$
$x=27$
Vậy $x=27$
e,
$3^{2x+2}=9^{10}$
$3^{2x+2}=(3^2)^{10}$
$3^{2x+2}=3^{20}$
$2x+2=20$
$2x=18$
$x=9$
Vậy $x=9$
f,
$(\dfrac{3}{5})^x=(\dfrac{9}{25})^3$
$(\dfrac{3}{5})^x=[(\dfrac{3}{5})^2]^3$
$(\dfrac{3}{5}^x=(\dfrac{3}{5})^6$
$x=6$
Vậy $x=6$
