\(\frac{-5}{9}.\frac{13}{28}-\frac{13}{28}.\frac{4}{9}\)
= \(\frac{13}{28}.\left(\frac{-5}{9}-\frac{4}{9}\right)\)
= \(\frac{13}{28}.\left(-1\right)=\frac{-13}{28}\)
~~~
#Sunrise
Tính tổng sau : S = 2/5*9 +2/9.13+2/13*17+......+2/97*101
Bài 1 : Tìm x biết :
x + 4/5.9 + 4/ 9.13 + 4/ 13 .15 + ... + 4/41.45 = -37/45
Bài 2 : x - 20/11.13 - 20/13.15 - ...-20/53.55= 3/11
Bài 3 : Tìm x biết
1/21 + 1/28 + 1/36 + ...+ 2/ x(x+1)=2/9
-5/9 . 13/28 - 13/28 . 4/9
-5/9 x 13/28 - 13/28 x 4/9
E=5/9.13+7/9.25+13/19.25+31/19.69
Tính
E= 5/9.13 + 7/9.25 + 13/19.25 + 31/19.69
Tính:
-5/9.13 -7/9.25 - 13 / 9.25 - 31 / 19. 69
Tính : A = \(\frac{-5}{9}\times\frac{13}{28}-\frac{13}{28}\times\frac{4}{9}\)
\(\frac{-5}{9.13}-\frac{7}{9.25}-\frac{13}{19.25}-\frac{31}{19.69}\)