=> B/2 = 1/6 + 1/12 + 1/20 +...+ 1/90
= 1/2.3 + 1/3.4 + 1/4.5 +... +1/9.10
=1/2 - 1/3 + 1/3 -...+ 1/9 -1/10
=1/2-1/10
=> B = 1-1/5 = 4/5
Tính:1 /10 +1 /15 +1 /21 +1 /28 +1 /36 +1 /45 Help mik với mik cần gấp!!!!!!
1/3+1/6+1/10+1/15+1/21+1/28+1/36+1/45
1+1/3+1/6+1/10+1/15+1/21+1/28+1/36+1/45
p=1/3 +1/6 +1/10 +1/15 +1/21 +1/28 +1/36 +1/45 giúp mk với
(1/3-1).(1/6-1).(1/10-1).(1/15-1).(1/21-1).(1/28-1).(1/36-1)
A=1+1/3+1/6+1/10+1/15+1/21+1/28+1/36+1/45
So sánh A với 2
#Toán lớp 5 + 6
A=\(\dfrac{1}{3}+\dfrac{1}{6}+\dfrac{1}{10}+\dfrac{1}{15}+\dfrac{1}{21}+\dfrac{1}{28}+\dfrac{1}{36}\)
tính giá trị của biểu thức
E=1/3+1/6+1/10+1/15+1/21+1/28+1/36
B = ( 1/3 - 1 )( 1/10 - 1 ) ( 1/15 - 1 ) ( 1/21 - 1 ) ( 1/28 - 1 )( 1/36 - 1 )
