Câu 4: Cặp phân số nào sau đây không có cùng mẫu số?
A. \(\dfrac{3}{15}và\dfrac{9}{15}\) | B. \(\dfrac{3}{15}và\dfrac{8}{15}\) |
C. \(\dfrac{3}{15}và\dfrac{9}{25}\) | D. \(\dfrac{2}{15}và\dfrac{9}{15}\) |
tinh C=9*5^20*27^9-3*9^15*25^9/7*3^29*125^6-3*3^9*15^19
giúp gấp, trình bày ra ạ. ai trl nhanh tick. " ." là nhân
-1/3 . 5/9
-3/7 . 5/15
-7/3.9/21
(-3/10) . (- -15/2)
-15/9 . 5/9
(-5).5/11
a ) - 8 / 24 + - 4 / 12
b ) - 20 / 35 + 16 / 24
c ) - 3 / 9 + - 6 / 15
d ) 3 / 13 - 4 / 10
e ) 5 / 17 - 9 / 15
g ) 9 / 18 - 6 / 15 + 3 / - 9
h ) 5 / 4 - 1 / 2 + - 7 / 8
\(\dfrac{-1}{3}.\dfrac{2}{5}\)
\(\dfrac{-3}{7}.\dfrac{4}{15}\)
\(\dfrac{-9}{3}.\dfrac{15}{27}\)
\(\dfrac{-5}{6}.\)( -12 )
\(\dfrac{-12}{4}.\dfrac{8}{9}\)
\(-3.\dfrac{7}{6}\)
\(\dfrac{-15}{9}.\dfrac{27}{5}\)
\(-9.\dfrac{4}{27}\)
-2/9+8/15+5/3-7/9+7/15
-5/9 + 7/15 - 4/9 + 3/12 + 8/15
\(\dfrac{x}{15}=\dfrac{3}{5}-\dfrac{-2}{3}\) ok
\(\Rightarrow\dfrac{x}{15}=\dfrac{9}{15}+\dfrac{10}{15}\)
\(\Rightarrow\dfrac{x}{15}=\dfrac{19}{15}\)
\(\Rightarrow x=19\)
-2/9+8/15+1 2/3-7/9+-7/-15