tìm x biết

a) \(\dfrac{2}{5}-\left(\dfrac{1}{10}-x\right)=\left(\dfrac{-2}{5}-\dfrac{1}{2}\right)^2\)

b) \(\dfrac{2}{5}-\dfrac{3}{5}\left(x-2\right)=\left(\dfrac{-1}{2}\right)^3-\left(\dfrac{3}{4}\right)^3.\left(-2\right)^2\)

1 tính

a. \((\left|-5\right|7^4+3^2.2\dfrac{2}{5}):(7^5.125.7^3.50)\)

b. \((\dfrac{3^2}{9}.\dfrac{3^3}{81})^{12}:(\dfrac{3^6}{81^2})^{10}\)

c. \([(\dfrac{1}{2})^2.(\dfrac{1}{3})^4.\dfrac{2}{7}]:\left(\dfrac{1}{3}\right)^{-2}.\dfrac{-2^2}{7}\)

\(8^x\): \(4^x\)=16

Bài 1: Tính:

a) \(^{27^n}\) : \(^{3^n}\) = 9

b)\(\dfrac{25}{5^n}\)=5

c)\(\dfrac{81}{\left(-3\right)^n}\)=-243

d)\(\dfrac{1}{2}\) . \(^{2^n}\)+\(^{4.2^n}\)=9.25

Giúp mk nha mọi người. Mấy dấu chấm là dấu nhân đó

(x+\(\dfrac{3}{2}\))2=\(\dfrac{9}{49}\)

\(\dfrac{3^6.45^4-15^3.5^{-9}}{27^4.25^3+45^6}\)

x2-1/10=23/90

B1 Tính :

a, ( \(\dfrac{-1}{3}\))2 . ( \(\dfrac{-1}{3}\))

b, ( \(\dfrac{1}{7}\))7 . 77 ( 7 mũ 7 nha )

c, 8/4 ( 8 mũ 4 , 4 mũ 4 )

d, 90/15 ( 90 mũ 3 , 15 mũ 3 )

e, 2.3+2.3/10 ( 3 mũ 3, cả 2 số 3 đó ) còn 2 bên phải là mũ 3

tính:

\(\dfrac{\left(-6\right)^6}{216}\) \(\dfrac{64}{\left(-4\right)^5}\) \(\dfrac{900}{\left(-30\right)^3}\) \(\dfrac{225}{\left(-15\right)^3}\)

giúp giùm nha cần gấp lắm

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