I
C1: A
C2: C
C3: D
C4: A
C5: C
C6: B
II
Câu 1:
\(a,\dfrac{23}{-7}.\dfrac{7}{12}+\dfrac{5}{12}=\dfrac{-23}{12}+\dfrac{5}{12}=\dfrac{-18}{12}=\dfrac{-3}{2}\dfrac{ }{ }\)
\(b,\dfrac{9}{5}-\dfrac{4}{5}:\left(\dfrac{4}{3}-\dfrac{1}{4}\right)^2-\left(-2024\right)^0\)
\(=\dfrac{9}{5}-\dfrac{4}{5}:\left(\dfrac{16}{12}-\dfrac{3}{12}\right)^2-1\)
\(=\dfrac{9}{5}-\dfrac{4}{5}:\left(\dfrac{13}{12}\right)^2-1\)
\(=\dfrac{9}{5}-\dfrac{4}{5}:\dfrac{169}{144}-1\)
\(=\dfrac{9}{5}-\dfrac{4}{5}.\dfrac{144}{169}-1\)
\(=\dfrac{9}{5}-\dfrac{576}{845}-1\)
\(=\dfrac{1521}{845}-\dfrac{576}{845}-\dfrac{845}{845}\)
\(=\dfrac{1521-576-845}{845}\)
\(=\dfrac{100}{845}\)
\(=\dfrac{20}{169}\)
Câu 2:
\(a,-4x-\dfrac{19}{2}=-\dfrac{15}{4}\)
\(-4x=\dfrac{-15}{4}+\dfrac{19}{2}\)
\(-4x=\dfrac{-15}{4}+\dfrac{38}{4}\)
\(-4x=\dfrac{23}{4}\)
\(x=\dfrac{23}{4}:-4\)
\(x=\dfrac{23}{4}.\dfrac{-1}{4}\)
\(x=\dfrac{-23}{16}\)
Vậy....
\(b,\dfrac{-24}{5}.\left(\dfrac{-25}{2}-x\right)=\left(\dfrac{26}{16}\right)^4\)
\(\dfrac{-24}{5}.\left(\dfrac{-25}{2}-x\right)=16\)
\(\dfrac{-25}{2}-x=16:\dfrac{-24}{5}\)
\(\dfrac{-25}{2}-x=16.\dfrac{-5}{24}\)
\(\dfrac{-25}{2}-x=\dfrac{-10}{3}\)
\(x=\dfrac{-25}{2}-\dfrac{-10}{3}\)
\(x=\dfrac{-55}{6}\)
Vậy .....
