Bài giải

\(25\cdot11=275\)

\(99\cdot45\)\(=4455\)

25 x 11 = 275
99 x 45 = 4455
Chúc bạn học tốt!  mong ji

25x11= 275

99x 45= 4455

13x11=143.kick nha

\(13x11=143\)

13 x 11 = 143

250+25=275

275 ko dùng mt ns thề tk nha

25 x 11 = 275

k nha

11x11=121

12x11=132

13x11=143

Đổi tk ko mn

11 x 11 = 121

12 x 11 = 132

13 x 11 = 143

K mik xg mik k lại cho 

Hok tốt

11x11=121

12x11=132

13x11=143

_Hok tốt_

Đổi tk .

= 11 x ( 46 + 13 + 41 )

= 11 x 100

= 1100

11x46+13x11+41x11

= 11x( 46+13+41)

= 11x 100

=1100

11x46 + 13x11 + 41x11

= 11 x (46 + 13 + 41)

= 11 x 100

= 1100

a) \(\dfrac{81\times49}{7\times8}=\dfrac{81\times7\times7}{7\times8}=\dfrac{81\times7}{8}=\dfrac{567}{8}\)

b) \(\dfrac{105\times69}{3\times35}=\dfrac{3\times35\times69}{3\times35}=69\)

c) \(\dfrac{77\times39}{13\times11}=\dfrac{11\times7\times13\times3}{13\times11}=7\times3=21\)

a) \(\dfrac{81x49}{7x8}=\dfrac{81x7x7}{7x8}=\dfrac{81x7}{8}=\dfrac{567}{8}=70,875\)

b) \(\dfrac{105x69}{3x35}=\dfrac{3x35x69}{3x35}=\dfrac{69}{1}=69\)

c) \(\dfrac{77x39}{13x11}=\dfrac{11x7x3x13}{13x11}=\dfrac{7x3}{1}=\dfrac{21}{1}=21\)

khó quá ai mà biết chứ ?

Bài 1 :

\(a)\frac{-17}{30}-\frac{11}{-15}+\left(-\frac{7}{12}\right)\)

\(=\frac{1}{6}+\left(-\frac{7}{12}\right)\)

\(=-\frac{5}{12}\)

\(b)-\frac{5}{9}+\frac{5}{9}:\left(1\frac{2}{3}-2\frac{1}{12}\right)\)

\(=-\frac{5}{9}+\frac{5}{9}:\left(\frac{5}{3}-\frac{25}{12}\right)\)

\(=-\frac{5}{9}+\frac{5}{9}:\left(-\frac{5}{12}\right)\)

\(=-\frac{5}{9}+\left(-\frac{2}{3}\right)\)

\(=-\frac{1}{9}\)

\(c)-\frac{7}{25}\times\frac{11}{13}+\left(-\frac{7}{25}\right)\times\frac{2}{13}-\frac{18}{25}\)

\(=-\frac{77}{325}+\left(-\frac{14}{325}\right)-\frac{18}{25}\)

\(=-\frac{7}{25}-\frac{18}{25}\)

\(=-1\)