chieu dai cua ssn van dong do la:800m+100m=900m

dien tich svd do la 900×800=720000m

a. 8,24 + 3,69 + 2,31                b. 5,92 + 0,44 + 5,56 + 4,48

= 8,24 + ( 3,69 + 2,31 )             = ( 5,92 + 4,48 ) + ( 0,44 + 5,56 )

= 8,24 +           6                      =        10,4        +          6

=       14,24                              =                  16,4

UCLN la 4

UC la:+/-(1,2,4)

so hs do la BC cua 6va11 tu khoang 50-100 suy ra so hs la 66 em

S=-5+(-5)^2+(-5)^3+...+(-5)^100

-5S=(-5)^2+(-5)^3+...+(-5)^100+(-5)^101

-5S-S=-6S=(-5)^101+5

[(-5)^101+5]÷6

\(\left(1-\frac{1}{2}\right)\times\left(1-\frac{1}{3}\right)\times\left(1-\frac{1}{4}\right)\times\left(1-\frac{1}{5}\right)\times...\times\left(1-\frac{1}{2003}\right)\times\left(1-\frac{1}{2004}\right)\)

\(=\left(\frac{2}{2}-\frac{1}{2}\right)\times\left(\frac{3}{3}-\frac{1}{3}\right)\times...\times\left(\frac{2003}{2003}-\frac{1}{2003}\right)\times\left(\frac{2004}{2004}-\frac{1}{2004}\right)\)

\(=\frac{1}{2}\times\frac{2}{3}\times...\times\frac{2002}{2003}\times\frac{2003}{2004}\)

\(=\frac{1\times2\times...\times2002\times2003}{2\times3\times...\times2003\times2004}=\frac{1}{2004}\)

24,7dm=2,47m

2,34kg=0,0234 ta

345,04m=3,4504km

123,08cm=1,2308m

705kg=0,705tan

1045g=1,045kg

cho diemO nam trong tam giac ABC

a) CMR: goc BOC > goc BAC

b) neu diem Ola giao diem cua 2 tia phan giac cua goc B va GoC.CMR GOC BOC la goc tu?

ta co: goc A=goc E (gia thiet)

EF=AC(gt)

FD=BC(gt)

suy ra tam giac EFD=tgACB