16:0,25+8:0,5x58+1,6x3,8:0,01

=16x4+16x58+1,6x3,8x100

=16x(4+58)+16x38

=16x(62+38)

=16x100

=1600

Đặt A=1+4+7+...+52+55

Số số hạng của dãy số là:

\(\frac{55-1}{3}+1=\frac{54}{3}+1=18+1=19\) (số)

Tổng của dãy số là: \(\left(55+1\right)\times\frac{19}{2}=56\times\frac{19}{2}=28\times19=532\)

Ta có: \(\frac{16:0,25+8:0,5\times58+1,6\times3,8:0,01}{1+4+7+\cdots+55-516}\)

\(=\frac{1600}{532-516}=\frac{1600}{16}=100\)

a) 19/35+15/19+16/35+23/19+4/15+11/15 = (19/35+16/35)+(15/19+23/19)+(4/15+11/15) = 1+2+1 = 4 b)4/17-7/15+13/17-8/15+5/8-7/16 = (4/17+13/17)-(7/15-8/15)+(5/8-7/16) = 1-1+3/16 =3/16

Câu a:

\(\frac{19}{35}\) + \(\frac{15}{19}\) + \(\frac{16}{35}\) + \(\frac{23}{19}\) + \(\frac{4}{15}\) + \(\frac{11}{15}\)

= (\(\frac{19}{35}\) + \(\frac{16}{35}\)) + (\(\frac{15}{19}\) + \(\frac{23}{19}\)) + (\(\frac{4}{15}+\frac{11}{15}\))

= \(\frac{35}{35}\) + \(\frac{38}{19}\) + \(\frac{15}{15}\)

= 1 + 2+ 1

= 3 + 1

= 4

17 x 513 - 17 x 10 - 17 x 3

= 17 x (513 - 10 - 3)

= 17 x 500

= 8500

17x513-17-17x10

=17x513-17x1-17x10

=17x(513-1-10)

=17x502

=8534

17 x 513 - 17 - 17 x 10   

= 17 x (513 - 1 - 10)

= 17 x 502

= 8534

40 x 86 x 25

= 25 x 4 x 10 x 86

= 100 x 860

= 86000

\(\dfrac{7}{5}\times\dfrac{11}{24}\times\dfrac{5}{7}\times\dfrac{24}{55}\\ =\left(\dfrac{7}{5}\times\dfrac{5}{7}\right)\times\left(\dfrac{11}{24}\times\dfrac{24}{55}\right)\\ =1\times\dfrac{1}{5}\\ =\dfrac{1}{5}\)

\(\dfrac{7x11x5x24}{5x24x7x55}\)=\(\dfrac{11}{55}\)=\(\dfrac{1}{5}\)

a)1996000

b)7200

ta có: A:0.25=A x 4

Ta có

A)(40.7-17.5)x4

=23.2x4=92.8

B)ko biết:)))))))))))))))))))))))))))

Lời giải:

$=(0,25\times 0,04)\times 3,6+ 360+3,6\times 8$

$=0,01\times 3,6+360+28,8$

$=0,036+360+28,8=388,836$

=55(25-20+4+1)

=55.10

=550

=55(25-20+4+1)
=55

Tàu là trùm