Tìm số nguyên dương n biết

a)\(\frac{1}{8}\).\(8^n\)=\(2^9\)

b)4.\(2^5\)≤\(2^n\)< \(4^5\)

B = \(\left(5^2+1\right)\)\(\left(5^4+1\right)\)\(\left(5^8+1\right)\)\(\left(5^{16}+1\right)\) \(\left(5^{32}+1\right)\)

Rút gọn:

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

b) (2x+3) (2x-3)-\(\left(x+5\right)^2\)

c) \(^{\left(x+1\right)^2}\)-\(\left(x-1\right)^2\)

d) 5(x+2) (x-2)-\(\frac{1}{2}\)\(\left(6-8x\right)^2\)

a) \(\frac{1}{2}\)\(^{^{ }x^2}\)(4x-5)+2\(^{^{ }}x^2\)-9 = 0

b)5x(7x+3-8\(^{^{ }}x^2\)-5x = 0