a: =-1+17/20=-3/20

b: =(28/60-33/60)*(-25/3)

=(-1/12)*(-25/3)=1/12*25/3=25/36

c: \(=\dfrac{1}{3}\cdot\dfrac{1}{3}=\dfrac{1}{9}\)

a) \(4^8\cdot4^4=\left(2^2\right)^8\cdot\left(2^2\right)^4=2^{16}\cdot2^8=2^{16+8}=2^{24}\)

b) \(5^{12}\cdot7-5^{11}\cdot10\)

\(=5^{11}\cdot\left(5\cdot7-10\right)=5^{11}\cdot\left(35-10\right)=5^{11}\cdot25\)

\(=5^{11}\cdot5^2=5^{11+2}=5^{13}\)

d) \(27^{16}:9^{10}\)

\(=\left(3^3\right)^{16}:\left(3^2\right)^{10}=3^{48}:3^{20}=3^{48-20}=3^{28}\)

e) \(125^3:25^4=\left(5^3\right)^3:\left(5^2\right)^4=5^9:5^8=5^{9-8}=5\)

f) \(24^4:3^4-32^{12}:16^{12}\)

\(=\left(24:4\right)^4-\left(32:16\right)^{12}\)

\(=6^4-2^{12}\)

\(=2^4\cdot\left(3^4-2^8\right)=2^4\cdot-175=-2800\)

a)\(\frac{16}{20}=\frac{4}{5};\frac{9}{15}=\frac{3}{5}\)

Vì 4>3\(\Rightarrow\frac{4}{5}>\frac{3}{5}\) hay \(\frac{16}{20}>\frac{9}{15}\)

Vậy \(\frac{16}{20}>\frac{9}{15}\)

b) \(\frac{6}{8}=\frac{3}{4};\frac{3}{12}=\frac{1}{4}\)

Vì 3>1 \(\Rightarrow\frac{3}{4}>\frac{1}{4}\) hay \(\frac{6}{8}=\frac{3}{12}\)

Vậy \(\frac{6}{8}=\frac{3}{12}\)

c) \(\frac{15}{25}=\frac{3}{5};\frac{36}{45}=\frac{4}{5}\)

Vì 3<4 \(\Rightarrow\frac{3}{5}<\frac{4}{5}\) hay \(\frac{15}{25}<\frac{36}{45}\)

Vậy \(\frac{15}{25}<\frac{36}{45}\)

Neu ban nao dung thi minh tich cho nhe

_{minh khong biet dap an cua cau hoi nay} 

\(a,\dfrac{1}{2}=\dfrac{2}{4}=\dfrac{4}{8}=\dfrac{3}{6}\\ b,\dfrac{1}{4}=\dfrac{2}{8}=\dfrac{3}{12}=\dfrac{5}{20}\\ c,\dfrac{2}{5}=\dfrac{8}{20}=\dfrac{10}{25}\)

\(\dfrac{15^2\cdot16^4-15^3\cdot16^3}{12^2\cdot20^3-20^2\cdot12^3}\)
\(=\dfrac{15^2\cdot16^3\left(16-15\right)}{12^2\cdot20^2\left(20-12\right)}\)
\(=\dfrac{3^2\cdot5^2\cdot2^{12}}{2^4\cdot3^2\cdot2^4\cdot5^2\cdot2^3}\)
\(=\dfrac{2^{12}}{2^{11}}=2^1=2\)
 

ko bt

Đề bài là tính hả bạn?