Question

B1: tính 

B=(\(3^4.57-9^2.21\)):\(3^5\)

b2:tìm x \(\in Z\)

a)\(\left(x-1\right)^{x+2}=\left(x-1\right)^{x+4}\)

b)\(\frac{1}{4}.\frac{2}{6}.\frac{3}{8}.\frac{4}{10}.......\frac{31}{64}=2^x\)

 

Answer 1

xin loi ban to chua hoc toi

Answer 2

xin loi nha to chua hoc bai nay nen ko giai duoc

Answer 3

\(B1,\)

\(B=\left(3^4.57-9^2.21\right):3^5\)

\(=\left(81.57-81.21\right):243\)

\(=\left[81.\left(57-21\right)\right]:243\)

\(=\left[81.36\right]:243\)

\(=2916:243\)

\(=12\)