64x100+50x44

=2200+6400

=8600

1026+2774

=3800

mình làm đúng ko vậy

TL:
= 3800

nhé

K CHO MK NHAAAAAAA
BNNNNNNNNNNNNNNNNNNNNNNNNNN

~~HT~~
 

TL:

64x100+50x44

=2200+6400

=8600

1026+2774

=3800

HT

-79-79.99

=-79+(-79).99

=-79.100=-7900

19-42(-19)+38.5

=19.1+42.19+19.10

=19(1+42+10)

=19.53

=1007

-158,99

855,5

tick nha

-79- 79 . 99 = 0 câu sau khó quá

Bài gì mà lộn xộn vậy trời . Không hiểu gì luôn .

a. 64 x 50 + 44 x 100

= 32 x 2 x 50 + 44 x 100

= 32 x 100 + 44 x 100

= (32 + 44) x 100

= 76 x 100

= 7600

b. 27 x 38 + 146 x 19

= 27 x 38 + 73 x 19 x 2

= 27 x 38 + 73 x 38

= (27 + 73) x 38

= 100 x 38

= 3800

a/b = 7600/3800 = 2

\(64\times50+44\times100\)

\(=32\times2\times50+44\times100\)

\(=\left(32+44\right)\times100\)

\(=76\times100=7600\)

64x50+44x100

=32x2x50+44x100

=32x(50x2)+44x100

=32x100+44x100

=(32+44)x100

=76x100

=7600

A nha em

Chọn A

A

34 x 15 + 34 x 85

= 34 x ( 15 + 85 )

= 34 x 100 = 3400

14 x 43 + 86 x 43

= ( 14 + 86 ) x 43

= 100 x 43 = 4300

tính tổng dãy số có quy luật

a) -79 - 79.99 = -79(1 + 99) = -79.100 = -7900

b) -123.47 + 47.23 = -47(123 - 23) = -47.100 = -4700

c) 19 - 42.(-19) + 38.5 = 19 + 42.19 + 38.5 = 19(1 + 42 + 10) = 19.53 = 20.53 - 53 = 1060 - 53 = 1007

\(x=\left(\dfrac{21}{19}-\dfrac{5}{19}\right)-\dfrac{24}{38}=\dfrac{4}{19}\)

\(\dfrac{24}{38}+x=\dfrac{21}{19}-\dfrac{5}{19}\\ \Rightarrow\dfrac{12}{19}+x=\dfrac{16}{19}\\ \Rightarrow x=\dfrac{16}{19}-\dfrac{12}{19}\\ \Rightarrow x=\dfrac{4}{19}\)

24/38+x= 16/19

x= 16/19-24/28

x= 16/19-6/7

x= -2/133

3 x 15 + 21 x 15 + 85 x 5

= 45 + 315 + 425

= 785

15 - 30 + 40 

= 25

21 + 19 - 50 + 10

= 0

\(\dfrac{1}{5}-\dfrac{1}{4}+2\)

\(=-\dfrac{1}{20}+2\)

\(=\dfrac{39}{20}\)

\(\left(\dfrac{1}{4}+\dfrac{1}{6}\right)\times\left(\dfrac{1}{2}-\dfrac{1}{4}\right)\)

\(=\dfrac{5}{12}\times\dfrac{1}{4}\)

\(=\dfrac{5}{12}\times\dfrac{3}{12}\)

\(=\dfrac{5}{48}\)

\(\dfrac{1}{10}+\dfrac{1}{5}-\dfrac{3}{4}\)

\(=-\dfrac{9}{20}\)

\(3\times15+21\times15+85\times5\\ =15\times\left(3+21\right)+425\\ =15\times24+425\\ =360+425\\ =785\)

\(15-30+40\\ =\left(15+40\right)-30\\ =55-30\\ =25\)

\(21+19-50+10\\ =\left(21+19\right)-\left(50-10\right)\\ =40-40\\ =0\)

\(\dfrac{1}{5}-\dfrac{1}{4}+2\)

\(=\dfrac{4}{20}-\dfrac{5}{20}+\dfrac{40}{20}\)

\(=\dfrac{\left(4+40\right)}{20}-\dfrac{5}{20}\)

\(=\dfrac{44}{20}-\dfrac{5}{20}\)

\(=\dfrac{39}{20}\)

\(\left(\dfrac{1}{4}+\dfrac{1}{6}\right)\times\left(\dfrac{1}{2}-\dfrac{1}{4}\right)\)

\(=\dfrac{5}{12}\times\dfrac{1}{4}\)

\(=\dfrac{5}{48}\)

\(\dfrac{1}{10}+\dfrac{1}{5}-\dfrac{3}{4}\)

\(=\dfrac{2}{20}+\dfrac{4}{20}-\dfrac{15}{20}\)

\(=\dfrac{6}{20}-\dfrac{15}{20}\)

\(=-\dfrac{9}{20}\)

Help meeeeeeeeeee