a) \(A=2^{n-1}+2.2^{n+3}-8.2^{n-4}-16.2^n\)

\(=2^{n-1}+2^{n+3+1}-2^{n-4+3}-2^{n+4}\)

\(=2^{n-1}+2^{n+4}-2^{n-1}-2^{n+4}\)

\(=0\)

b) \(B=\left(3^{n+1}-2.2^n\right)\left(3^{n+1}+2.2^n\right)-3^{2n+2}+\left(8.2^{n-2}\right)^2\)

\(=\left(3^{n+1}-2^{n+1}\right)\left(3^{n+1}-2^{n+1}\right)-3^{2n+2}+2^{2n+2}\)

\(=3^{2n+2}-2^{2n+2}-3^{2n+2}+2^{2n+2}\)

\(=0\)

a,

\(A=2^{n-1}+2.2^{n+3}-8.2^{n-4}-16.2^n\)

\(=2^{n-1}+2^{n+3+1}-2^{n-4+3}-2^{n+4}\)

\(=2.2^{n-1}+2.2^{n+4}=2^n+2^{n+5}\)

b,

\(B=\left(3^{n+1}-2.2^n\right)\left(3^{n+1}+2.2^n\right)-3^{2n+2}+\left(8.2^{n-2}\right)^2\)

\(=\left(3^{n+1}\right)^2-\left(2.2^n\right)^2-\left(3^{n+1}\right)^2+\left(2^{n-2+3}\right)^2\)

\(=-2^{n+1}+2^{n+1}=0\)

= 0 nha bạn 

\(A=2^{n-1}+2^{n+4}-2^3\cdot2^{n-4}-2^4\cdot2^n\)

\(A=2^{n-1}+2^{n+4}-2^{n-1}-2^{n+4}\)

\(A=0\)

P = (x-1)(2x+3)

=> P=2x²+3x-2x-3

=> P=2x²+x-3

=> P=\(2x^2+x+\dfrac{1}{8}-\dfrac{25}{8}\)

=> P=2\(\left(x^2+\dfrac{1}{2}x+\dfrac{1}{16}\right)-\dfrac{25}{8}\)

=> P=\(2\left(x+\dfrac{1}{4}\right)^2-\dfrac{25}{8}\)

=> min P =\(\dfrac{-25}{8}\) khi \(x+\dfrac{1}{4}=0\Rightarrow x=-\dfrac{1}{4}\)