Tính giá trị biểu thức

\(A=\left(\dfrac{ab}{2}-\dfrac{6ab}{7}\right):\dfrac{5b^2}{14}biết;a=\dfrac{2007}{2010},b=\dfrac{2015}{2016}\)

rút gọn A= 1+22+24+...+250

Chứng minh 810-89-88 chia hết cho 11

Tìm x:

(2-1)x+2=(x-1)x+4

Giải giúp mik vs

Tính:

\(\left(\dfrac{1}{10}\right)^{10}.\left(\dfrac{1}{2}\right)^{50}\)

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=\(\dfrac{9}{49}\)