Question

se considera numerele reale
x=
$(1 - \frac{1}{2} )(1 - \frac{1}{3} )(1 - \frac{1}{4} )(1 - \frac{1}{5} )$
si y=
$(1 - \frac{2}{5} - \frac{1}{4} ) \div ( \frac{3}{4} - \frac{5}{9} )$
aratati ca media aritmetica se a numerelor x si y este egala cu 1.

mulțumesc!​

Answer 1

Răspuns:

vezi atașament.............

Answer 2

x=(1-1/2)(1-1/3)(1-1/4)(1-1/5)

x=(2/2-1/2)(3/3-1/3)(4/4-1/4)(5/5-1/5)

x=1/2×2/3×3/4×4/5

x=1/5

y=(1-2/5-1/4):(3/4-5/9)

y=(20/20-8/20-5/20):(27/36-20/36)

y=(12/20-5/20):7/36

y=7/20:7/36

y=7/20×36/7

y=9/5

mₐ=(x+y)/2

mₐ=(1/5+9/5)/2

mₐ=10/5/2

mₐ=2/2

mₐ=1