\(=\frac{74+69}{75+89}\)\(=\frac{10}{13}\)

74 x 158 + 69

=11692 + 69

=23453

158 x 75 - 89

=11850 - 89

=11672

74x158+69 = 11692 + 69 = 11761

158x75-89 = 11850 - 89 = 11761

I think so !!

Bạn phải tự suy nghĩ chứ 

:)    ( ko bt )

\(A=\)\(\frac{1}{2}+\frac{5}{6}+\frac{11}{12}+\frac{19}{20}+\frac{29}{30}+\frac{41}{42}+\frac{55}{56}+\frac{71}{72}+\frac{89}{90}\)

\(A=\)\(1-\frac{1}{2}+1-\frac{1}{6}+1-\frac{1}{12}+1-\frac{1}{20}+1-\frac{1}{30}+1-\frac{1}{42}+1-\frac{1}{56}+1-\frac{1}{72}+1-\frac{1}{90}\)

\(A=\)\(9-\left(\frac{1}{2}+\frac{1}{6}+\frac{1}{12}+\frac{1}{20}+\frac{1}{30}+\frac{1}{42}+\frac{1}{56}+\frac{1}{72}+\frac{1}{90}\right)\)

\(A=\)\(9-\left(\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+\frac{1}{4.5}+\frac{1}{5.6}+\frac{1}{6.7}+\frac{1}{7.8}+\frac{1}{8.9}+\frac{1}{9.10}\right)\)

\(A=\)\(9-\left(1-\frac{1}{10}\right)\)

\(A=\)\(9-\frac{9}{10}\)

\(A=\)\(\frac{81}{10}\)

A=(1-1/2)+(1-1/6)+...+(1-89/90)

A=1x9-(1/2+1/6+...+1/90)

A=9-(1/1x2+1/2x3+...+1/9x10)

A=9-(1-1/2+1/2-1/3+1/3+...+1/9 -1/10)

A=9-(1-1/10)

A=9-9/10

A=81/10=8,1

hok tốt nhé

\(=47.69-31.47.\left(-1\right)\\ =47.\left(69+31\right)\\ =47.100=4700\)

\(47\cdot69-31\cdot(-47)\\=47\cdot69-31\cdot(-1)\cdot47\\=47\cdot69+31\cdot47\\=47\cdot(69+31)\\=47\cdot100\\=4700\)

=47.69−31.47.(−1)

=47.(69+31)

=47.100

=4700

Tick mik nha :D

4 6 .   9 5 +   6 9 .   120 8 4 .   3 12 − 6 11 = 2 2 6 . 3 2 5 + 2 9 .3 9 .2 3 .3.5 2 3 4 .3 12 − 2 11 .3 11 = 2 12 .3 10 + 2 12 .3 10 .5 2 12 .3 12 − 2 11 .3 11 = 2 12 .3 10 1 + 5 2 11 .3 11 2.3 − 1 = 2.6 3.5 = 4 5

bn chs blox fruit ko

=(9,8-8,9)+(8,7-7,8)+...+(2,1-1,2)

=0,9+0,9+...+0,9

=0,9*8=7,2

(-69) + (-14) + 56 - (-78) - (+97) - (-46)

= -69 - 14 + 56 + 78 - 97 + 46

= (-69 - 14 - 97) + (56 + 78 + 46)

= (-180) + 180

= 0

Chắc là giải kiểu vậy. :3