câu 1 b \(\left(\dfrac{1}{5}\right)\)mũ mấy v bạn?
Câu 1:
a: \(=\dfrac{3}{5}\left(8+\dfrac{3}{7}-23-\dfrac{3}{7}\right)=-15\cdot\dfrac{3}{5}=-9\)
\(\text{a)}8\dfrac{3}{7}:\dfrac{5}{3}-23\dfrac{3}{7}:\dfrac{5}{3}\) \(\text{b)}\sqrt{\dfrac{1}{81}}-\left(\dfrac{-1}{3}\right)^2:\dfrac{5}{9}+1^5.\left(\dfrac{1}{5}\right)^0\)
\(=\dfrac{59}{7}:\dfrac{5}{3}-\dfrac{164}{7}:\dfrac{5}{3}\) \(=\dfrac{1}{9}-\dfrac{1}{9}.\dfrac{9}{5}+1.1\)
\(=\dfrac{5}{3}:\left(\dfrac{59}{7}-\dfrac{164}{7}\right)\) \(=\dfrac{1}{9}-\dfrac{1}{5}+1\)
\(=\dfrac{5}{3}:\left(-15\right)\) \(=\left(\dfrac{-4}{45}\right)+1\)
\(=\dfrac{-1}{9}\) \(=\dfrac{41}{45}\)
\(\text{2)Tìm x,biết:}\)
\(\text{a)}2.\left|x-\dfrac{7}{6}\right|-3=7\)
\(2.\left|x-\dfrac{7}{6}\right|\) \(=7+3=10\)
\(\left|x-\dfrac{7}{6}\right|\) \(=10:2=5\)
\(\text{Vậy }x-\dfrac{7}{6}=5\)
\(x\) \(=5+\dfrac{7}{6}=\dfrac{37}{6}\)
\(\text{hoặc }x-\dfrac{7}{6}=\left(-5\right)\)
\(x\) \(=\left(-5\right)+\dfrac{7}{6}=\dfrac{-23}{6}\)
\(\Rightarrow x\in\left\{\dfrac{37}{6};\left(\dfrac{-23}{6}\right)\right\}\)
\(\text{b)}\dfrac{2}{3}-1\dfrac{4}{15}x=\dfrac{-3}{5}\)
\(\dfrac{19}{15}x=\dfrac{2}{3}+\dfrac{3}{5}=\dfrac{19}{15}\)
\(x=\dfrac{19}{15}.\dfrac{15}{19}=1\)
