Tính A= (1-1/15).(1-1/21).(1-1/28)....(1-1/210)
Tính A = (1-1/15)*(1-1/21)*(1-1/28)*...*(1-1/210)
Tính kết quả A=(1-1/15)(1-1/21)(1-1/28)........(1-1/210)
( 1 - 1/15 ) x (1- 1/21 ) x ( 1 - 1/28 ) x .......... x ( 1 - 1/210 ) . tính tích
giuos mình nhé . mình cần khẩn cấp đó các bạn ơi
Tính giá trị biểu thức: (1-1/15) x (1-1/21) x(1-1/28) x...x (1-1/210)
Tính A=\(\left(1-\frac{1}{15}\right)\left(1-\frac{1}{21}\right)\left(1-\frac{1}{28}\right)...\left(1-\frac{1}{210}\right)\)
Tính: \(A=\left(1-\frac{1}{15}\right)\left(1-\frac{1}{21}\right)\left(1-\frac{1}{28}\right)...\left(1-\frac{1}{210}\right)\)
TÍNH A= \(\left(1-\frac{1}{15}\right)\left(1-\frac{1}{21}\right)\left(1-\frac{1}{28}\right)...\left(1-\frac{1}{210}\right)\)
\(A=\frac{14}{15}.\frac{20}{21}.\frac{27}{28}....\frac{209}{210}=\frac{28}{30}.\frac{40}{42}.\frac{54}{56}....\frac{418}{420}=\frac{4.7}{5.6}.\frac{5.8}{6.7}.\frac{6.9}{7.8}....\frac{19.22}{20.21}\)
\(=\frac{4.5.6...19}{5.6.7...20}.\frac{7.8.9...22}{6.7.8...21}=\frac{4}{20}.\frac{22}{6}=\frac{11}{5}\)
tinh
(1-1/15)(1-1/21)(1-1/28)...(1-1/210)
=14\15.20\21....209\210
=14.2\15.2.20.2\21.2....209.2\210.2
=4.7\5.6.5.8\6.7.....19.20\20.21
=4.5.6....19\5.6.7...20.7.8.9....22\6.7.8.....21
=4\20.22\6
=1\5-11\3
=11\15
k cho mik nha
Có chắc ko đó bạn
TÍNH GIÁ TRỊ BIỂU THỨC
A=\(\left(1-\frac{1}{15}\right)\left(1-\frac{1}{21}\right)\left(1-\frac{1}{28}\right)...\left(1-\frac{1}{210}\right)\)
\(\Rightarrow A=\frac{14}{15}.\frac{20}{21}.\frac{41}{42}.....\frac{209}{210}\)
\(=\frac{4.7}{5.6}.\frac{5.8}{6.7}.\frac{6.9}{7.8}.....\frac{19.22}{20.21}\)
\(=\frac{22}{6}=\frac{11}{3}\)