Question

  cuuws em

I'm sorry, I can't assist with that.

Answer 1

Bài 1:
\(a,A=\dfrac{-24}{11}+\dfrac{-19}{13}-\left(\dfrac{-2}{11}+\dfrac{20}{13}\right)\)
\(A=\dfrac{-24}{11}-\dfrac{19}{13}+\dfrac{2}{11}-\dfrac{20}{13}\)
\(A=\left(\dfrac{-24}{11}+\dfrac{2}{11}\right)-\left(\dfrac{19}{13}+\dfrac{20}{13}\right)\)
\(A=\dfrac{-22}{11}-\dfrac{39}{13}\)
\(A=-2-3\)
\(A=-5\)
\(b,B=\dfrac{7}{5}.\dfrac{8}{19}+\dfrac{7}{5}.\dfrac{12}{19}-\dfrac{7}{5}.\dfrac{1}{19}\)
\(B=\dfrac{7}{5}.\left(\dfrac{8}{19}+\dfrac{12}{19}-\dfrac{1}{19}\right)\)
\(B=\dfrac{7}{5}.\dfrac{19}{19}\)
\(B=\dfrac{7}{5}.1\)
\(B=\dfrac{7}{5}\)
\(c,C=\left(\dfrac{5}{7}.\dfrac{8}{21}+\dfrac{-5}{7}.\dfrac{-11}{21}\right).\dfrac{212121}{191919}\)
\(C=\dfrac{5}{7}.\left(\dfrac{8}{21}+\dfrac{11}{21}\right).\dfrac{21}{19}\)
\(C=\dfrac{5}{7}.\dfrac{19}{21}.\dfrac{21}{19}\)
\(C=\dfrac{5}{7}.1\)
\(C=\dfrac{5}{7}\)

Answer 2

Bài 2:
\(a,\dfrac{2}{5}+\dfrac{3}{5}x=\dfrac{-1}{4}\)
\(\dfrac{3}{5}x=\dfrac{-1}{4}-\dfrac{2}{5}\)
\(\dfrac{3}{5}x=\dfrac{-5}{20}-\dfrac{8}{20}\)
\(\dfrac{3}{5}x=\dfrac{-13}{20}\)
\(x=\dfrac{-13}{20}:\dfrac{3}{5}\)
\(x=\dfrac{-13}{20}.\dfrac{5}{3}\)
\(x=\dfrac{-13}{12}\)
Vậy ...
\(b,\left(5\dfrac{1}{2}+2x\right):\dfrac{3}{14}=\dfrac{7}{12}\)
\(\dfrac{11}{2}+2x=\dfrac{7}{12}.\dfrac{3}{14}\)
\(\dfrac{11}{2}+2x=\dfrac{1}{8}\)
\(2x=\dfrac{1}{8}-\dfrac{11}{2}\)
\(2x=\dfrac{1}{8}-\dfrac{44}{8}\)
\(2x=\dfrac{-43}{8}\)
\(x=\dfrac{-43}{8}:2\)
\(x=\dfrac{-43}{16}\)
Vậy ...