= 1449

Ủng hộ nha ! Thank you very much

=1,449 dung thi k

=22,5x(13+97)+25x(44,9+5,1)

=2475+1250

=3725

22,5 " 13 - 44,9 " 25 + 22,5 "97 - 5,1 " 25 

= 22,5 " 25  " { 97 - 44,9 + 5,1  - 13 }

= 562,5 " 34 

= 19125 nhé.

(22,5 x 13+22,5 x 97)-(44,9 x 25+5,1 x 25) 

=22,5 x (13+97)-(44,9 + 5,1) x 25

=22,5 x 110-50 x 25

=2475-1250

=1225

\(\frac{17}{25}\times\frac{13}{19}+\frac{17}{25}\times\frac{6}{19}\)

\(=\frac{17}{25}\times\left(\frac{13}{19}+\frac{6}{19}\right)\)

\(=\frac{17}{25}\times\frac{19}{19}\)

\(=\frac{17}{25}\times1\)

\(=\frac{17}{25}\)

_HT_

\(\dfrac{17}{25}\left(\dfrac{13}{19}+\dfrac{6}{19}\right)\)

\(=\dfrac{17}{25}.1=\dfrac{17}{25}\)

bấm lộn nha

a= 257 x (87+23)
=257 x 100 
=25700
b=712 x (25+74)+752
=75200
c=94100

Chuẩn luôn rồi 
Học tốt

49 × 365 - 365 × 39 = 49 × 365 - 39 × 365 = 49 - 39 × 365 = 10 × 365 = 3650

1 3 + 2 5 + 2 3 = 1 3 + 2 3 + 2 5 = 1 + 2 3 + 2 5 = 1 + 2 5 = 5 5 + 2 5 = 7 5

Tính thuận tiện :

\(\frac{12}{25}+\frac{3}{5}+\frac{13}{25}\)

= \(\frac{12}{25}+\frac{13}{25}+\frac{3}{5}\)

= \(\frac{25}{25}+\frac{3}{5}\)

= \(1+\frac{3}{5}\)

= \(\frac{5}{5}+\frac{3}{5}\)

= \(\frac{8}{5}\)

\(\frac{12}{25}+\frac{3}{5}+\frac{13}{25}\)

\(=\left(\frac{12}{25}+\frac{13}{25}\right)+\frac{3}{5}\)

\(=\frac{25}{25}+\frac{3}{5}\)

\(=1+\frac{3}{5}=\frac{8}{5}\)

\(\frac{12}{25}+\frac{3}{5}+\frac{13}{25}\)

\(=\left(\frac{12}{25}+\frac{13}{25}\right)+\frac{3}{5}\)

\(=\frac{25}{25}+\frac{3}{5}\)

\(=1+\frac{3}{5}\)

\(=\frac{8}{5}\)

87 + 94 + 13 + 6= ( 87 + 13) + (94 +6)

= 100 + 100

ai k mình mình k lại

1/10000 + 13/10000 + 25/10000 + 133/10000 = (1 + 13 + 25 + 133)/10000

                                                                  = 172/10000 = 43/2500

úm ba la xin tích