\(A=\frac{56}{209}x\frac{7}{19}:\frac{3}{11}+\frac{12}{19}\)

\(A=\frac{392}{3971}:\frac{3}{11}+\frac{12}{19}\)

\(A=\frac{392}{1083}+\frac{12}{19}\)

\(A=\frac{1076}{1083}\)

E = 7/19 . 8/11 + 7/19 . 3/11 +12/19

= 7/19 . ( 8/11 + 3/11 ) + 12/19

= 7/19 . 11/11 + 12/19

= 7/19 . 1 + 12/19

= 7/19 + 12/19

= 7 + 12 / 19

= 19/19

= 1

\(=\frac{7}{19}.\left(\frac{8}{11}+\frac{3}{11}\right)+\frac{12}{19}\)

\(=\frac{7}{19}.1+\frac{12}{19}\)

\(=1\)

\(\frac{7}{19}\).\(\frac{8}{11}\)+\(\frac{7}{19}\).\(\frac{3}{11}\)+\(\frac{12}{19}\)

=\(\frac{7}{19}\).1+\(\frac{12}{19}\)

=1

hok tốt

.+.+

=.1+

=1

hok tốt

\(1\)) \(\frac{7}{19}.\frac{8}{11}+\frac{7}{19}.\frac{3}{11}+\frac{12}{19}\)

\(=\frac{7}{19}\left(\frac{8}{11}+\frac{3}{11}\right)+\frac{12}{19}\)

\(=\frac{7}{19}+\frac{12}{19}\)

\(=1\)

\(2\)) \(\frac{\frac{2}{5}+\frac{2}{7}-\frac{2}{9}-\frac{2}{11}}{\frac{4}{5}+\frac{4}{7}-\frac{4}{9}-\frac{4}{11}}\)

\(=\frac{\frac{2}{5}+\frac{2}{7}-\frac{2}{9}-\frac{2}{11}}{2\left(\frac{2}{5}+\frac{2}{7}-\frac{2}{9}-\frac{2}{11}\right)}\)

\(=\frac{1}{2}\)

1. \(\frac{7}{19}\times\frac{8}{11}+\frac{7}{19}\times\frac{3}{11}+\frac{12}{19}\)

\(=\frac{7}{19}\left(\frac{8}{11}+\frac{3}{11}\right)+\frac{12}{19}\)

\(=\frac{7}{19}\times1+\frac{12}{19}=\frac{19}{19}=1\)

2. \(\frac{\frac{2}{5}+\frac{2}{7}-\frac{2}{9}-\frac{2}{11}}{\frac{4}{5}+\frac{4}{7}-\frac{4}{9}-\frac{4}{11}}\)

\(=\frac{\frac{2}{5}+\frac{2}{7}-\frac{2}{9}-\frac{2}{11}}{2\left(\frac{2}{5}+\frac{2}{7}-\frac{2}{9}-\frac{2}{11}\right)}=\frac{1}{2}\)

đề thiếu rùi bn p/s đó là bao nhiêu vậy

7/19 . 8/11 + 3/19 . 7/11 + ( -12/19 )

= 7/19 + 3/19 . 8/11  + 7/11 + ( -12/19 )

= 10/19 . 15/11 + ( -12/19 )

= 15/11 . 10/19 + ( -12/19 )

= 15/11 . ( -2/19 )

= -30/209

=\(\frac{7}{19}.\frac{8}{11}+\frac{7}{19}+\frac{3}{11}+\)\(\left(-\frac{12}{19}\right)\) (vì phép nhân có tính chất hoán đổi nên mk đổi tử của tích thứ 2 nhé)

= \(\frac{7}{19}.\left(\frac{8}{11}+\frac{3}{11}\right)=\frac{7}{19}.1=\frac{7}{19}\)

=\(\frac{7}{19}.\)\(\left(\frac{8}{11}+\frac{2}{11}-\frac{5}{11}\right)\)

=\(\frac{7}{19}.\frac{5}{11}\)

=\(\frac{35}{209}\)Tk mk nhen bn yêu , kb nx ak

- 3 phân số \(\frac{7}{19}\)lận mà bạn ? Đâu phải hai số đâu mà gộp lại -.-

= 7/19 x ( 8/11 + 5/11 - 2/11 )

= 7/19 x 1

= 7/19 k cho mik nhaa

a ) \(\frac{7}{19}.\frac{8}{11}+\frac{3}{11}.\frac{7}{19}+\frac{-12}{19}\)

\(=\frac{7}{19}.\left(\frac{8}{11}+\frac{3}{11}\right)+\frac{-12}{19}\)

\(=\frac{7}{19}.\frac{11}{11}+\frac{-12}{19}\)

\(=\frac{7}{19}.1+\frac{-12}{19}\)

\(=\frac{7}{19}+\frac{-12}{19}\)

\(=\frac{7+\left(-12\right)}{19}\)

\(=-\frac{5}{19}\)

b ) \(\frac{-7}{25}.\frac{39}{-14}.\frac{50}{78}=\frac{-7.39.50}{25.-14.78}=\frac{-1.1.2}{1.-2.2}=\frac{-2}{-4}=\frac{1}{2}\)

c ) \(\left(\frac{3}{8}+\frac{-3}{4}+\frac{7}{12}\right):\frac{5}{6}+\frac{1}{2}\)

\(=\frac{5}{24}:\frac{5}{6}+\frac{1}{2}\)

\(=\frac{5}{24}.\frac{6}{5}+\frac{1}{2}\)

\(=\frac{1}{4}+\frac{1}{2}\)

\(=\frac{3}{4}\)

a)\(\frac{7}{19}.\frac{8}{11}+\frac{3}{11}.\frac{7}{19}+\frac{-12}{19}=\frac{7}{19}.\frac{8}{11}+\frac{3}{11}.\frac{7}{19}+\frac{7}{19}.\frac{-12}{7}=\frac{7}{19}.\left(\frac{8}{11}+\frac{3}{11}+-\frac{12}{7}\right)=\frac{7}{19}.\left(\frac{-5}{7}\right)=-\frac{5}{19}\)

b)\(\frac{-7}{25}.\frac{39}{-14}.\frac{50}{78}=\frac{\left(-7\right).39.50}{25.\left(-14\right).78}=\frac{\left(-7\right).3.13.2.5.5}{5.5.\left(-7\right).2.2.13.3}=\frac{1}{2}\)

c)\(\left(\frac{3}{8}+\frac{-3}{4}+\frac{7}{12}\right):\frac{5}{6}+\frac{1}{2}=\frac{5}{24}:\frac{5}{6}+\frac{1}{2}=\frac{2}{7}+\frac{1}{2}=\frac{11}{14}\)

hoc kim dong ak