Question

1,tính:

a,\(\dfrac{1}{1-\dfrac{1}{1-\dfrac{1}{2}}}+\dfrac{1}{1-\dfrac{1}{1-\dfrac{1}{2}}}\)

b,\(\dfrac{1}{1-\dfrac{1}{1-\dfrac{1}{3}}}+\dfrac{1}{1-\dfrac{1}{1-\dfrac{1}{3}}}\)

Answer 1

Làm xong chắc mù mắt =(((

a) \(\dfrac{1}{1-\dfrac{1}{1-\dfrac{1}{2}}}+\dfrac{1}{1-\dfrac{1}{1-\dfrac{1}{2}}}=2\left(\dfrac{1}{1-\dfrac{1}{\dfrac{1}{2}}}\right)=2\left(\dfrac{1}{1-2}\right)=\dfrac{1}{-1}.2=-2\)

\(\dfrac{1}{1-\dfrac{1}{1-\dfrac{1}{3}}}+\dfrac{1}{1-\dfrac{1}{1-\dfrac{1}{3}}}=2\left(\dfrac{1}{1-\dfrac{1}{\dfrac{2}{3}}}\right)=2\left(\dfrac{1}{1-\dfrac{3}{2}}\right)=2\left(\dfrac{1}{-\dfrac{1}{2}}\right)=2\left(-2\right)=-4\)