( 1/3+1/6+1/10+1/15+1/21) : x =5/7
5/7: x = 5/7
x = 5/7 : 5/7
x = 1
tk giùm nhé! chúc học giỏi!
ta có : ( 1/3 + 1/6 + 1/10 + 1/15 + 1/21 ) :x =5/7
=> 5/7 : x = 5/7
=> x = 5/7 : 5/7
x = 1
vậy x=1
( 1/3 + 1/6 + 1/10 +1/15 + 1/21 ) : x = 5/7
5/7 : x = 5/7
x = 5/7 : 5/7
x = 1
h cho tớ đi
( 1/3 + 1/6 + 1/10 + 1/15 + 1/21 ) : x = 5/7
( 70 / 210 + 35 / 210 + 21 / 210 + 14 / 210 + 10 / 210 ) : x = 5 / 7
5 / 7 : x = 5/7
x = 5/7 : 5/7
x = 1
k cho minh nhe
