\(2\cdot8^{15}\cdot4\cdot8^{20}=\left(2\cdot4\right)\cdot8^{15+20}=8\cdot8^{35}=8^{36}\)

\(n=13\Rightarrow n.1=13.1\)

\(\Rightarrow\frac{n}{1}=\frac{13}{1}\)

\(\frac{1}{n}=\frac{1}{13}\)

\(\frac{n}{13}=\frac{1}{1}\)

\(\frac{13}{n}=\frac{1}{1}\)

B1)9x⁴+16y⁶-24x²y³=(3x²-4y³)²

B2)a)81-x⁴=(9-x²)(9+x²)=(3-x)(3+x)(9+x²)

b)(2x+y)²-1=(2x+y-1)(2x+y+1)

c)(+y+z)²-(x-y-z)²=(x+y+z-x+y+z)(x+y+z+x-y-z)=(2y+2z)2x=4x(y+z)

B3)

(12³+1)(12³-1)-3⁶.4⁶

=12⁶-1-(3.4)⁶

=12⁶-1-12⁶=-1

\(\left(\frac{4}{9}\right)^2\)

\(\left(\frac{4}{9}\right)^2\)

\(\left(\frac{2}{3}\right)^4\)

\(=\frac{4^2}{9^2}=\left(\frac{4}{9}\right)^2\)

\(\frac{8}{125}\)không thể viết được dưới dạng một luỹ thừa.

\(\frac{8}{27}=\left(\frac{2}{3}\right)^3\)

\(2^{24}=\left(2^3\right)^{21}=8^{21}\)

2²⁴= 8⁸

`2^24 = 2^(3.8) = (2^3)^8 = 8^8`

Ta có x^2 + 4x + 4 = x^2+2.x.2+2^2=(x+2)^2