Question

mong các bro giúp

Answer 1

\(A=\dfrac{7}{19}\times\dfrac{8}{11}+\dfrac{7}{19}\times\dfrac{3}{11}+\dfrac{12}{19}\)

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

\(=\dfrac{7}{19}+\dfrac{12}{19}=\dfrac{19}{19}=1\)

Answer 2

a: \(A=\dfrac{7}{19}\left(\dfrac{8}{11}+\dfrac{3}{11}\right)+\dfrac{12}{19}=\dfrac{7}{19}+\dfrac{12}{19}=1\)

b: \(B=\left(\dfrac{67}{111}+\dfrac{2}{33}-\dfrac{5}{117}\right)\cdot\dfrac{4-3-1}{12}=0\)

Answer 3

a)\(A=\dfrac{7}{19}.\dfrac{8}{11}+\dfrac{7}{19}.\dfrac{3}{11}+\dfrac{12}{19}\) 

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

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

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

       \(=\dfrac{19}{19}=1\)

b)\(B=\left(\dfrac{67}{111}+\dfrac{2}{33}-\dfrac{15}{117}\right)\left(\dfrac{1}{3}-\dfrac{1}{4}-\dfrac{1}{12}\right)\)

       \(=\left(\dfrac{67}{111}+\dfrac{2}{33}-\dfrac{5}{39}\right)\left(\dfrac{4}{12}-\dfrac{3}{12}-\dfrac{1}{12}\right)\)

       \(=\left(\dfrac{67}{111}+\dfrac{2}{33}-\dfrac{5}{39}\right).0=0\)

Answer 4

\(\)a)\(A=\dfrac{7}{19}.\dfrac{8}{11}+\dfrac{7}{19}.\dfrac{3}{11}+\dfrac{12}{19}\)

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

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

\(A=\dfrac{19}{19}=1\)

b)\(B=\left(\dfrac{67}{111}+\dfrac{2}{33}-\dfrac{15}{117}\right).\left(\dfrac{1}{3}-\dfrac{1}{4}-\dfrac{1}{12}\right)\)

\(B=\left(\dfrac{67}{111}+\dfrac{2}{33}-\dfrac{15}{117}\right).\left(\dfrac{4}{12}-\dfrac{3}{12}-\dfrac{1}{12}\right)\)

\(B=\left(\dfrac{67}{111}+\dfrac{2}{33}-\dfrac{15}{117}\right).0\)

\(B=0\)