Question

1)tính : M = \(\dfrac{8^{10}+4^{10}}{8^4+4^{11}}\)

2) Tìm tỉ số x/y , biết x,y thỏa mãn :

\(\dfrac{2x-y}{x+y}=\dfrac{2}{3}\)

Answer 1

1) \(M=\dfrac{8^{10}+4^{10}}{8^4+4^{11}}=\dfrac{2^{30}+2^{20}}{2^{12}+2^{22}}=\dfrac{2^{20}\left(2^{10}+1\right)}{2^{12}\left(2^{10}+1\right)}=\dfrac{2^{20}}{2^{12}}=256\)

2) \(\dfrac{2x-y}{x+y}=\dfrac{2}{3}\Leftrightarrow2x+2y=6x-3y\Leftrightarrow4x=5y\Leftrightarrow\dfrac{x}{y}=\dfrac{5}{4}\)