Bài 1: Dễ, tính máy tính là ra
Bài 2:
a) \(\dfrac{1}{5}+1\dfrac{1}{4}x=\dfrac{2}{3}\)
\(\Rightarrow1\dfrac{1}{4}x=\dfrac{7}{15}\Rightarrow x=\dfrac{28}{75}\)
Vậy \(x=\dfrac{28}{75}\)
b) \(\left(\dfrac{2}{7}x-1\dfrac{1}{2}x\right):\dfrac{2}{7}=\dfrac{-21}{4}\)
\(\Rightarrow\left(\dfrac{2}{7}x-\dfrac{3}{2}x\right):\dfrac{2}{7}=\dfrac{-21}{4}\)
\(\Rightarrow\dfrac{2}{7}x-\dfrac{3}{2}x=\dfrac{-3}{2}\)
\(\Rightarrow x\left(\dfrac{2}{7}-\dfrac{3}{2}\right)=\dfrac{-3}{2}\)
\(\Rightarrow\dfrac{-17}{14}x=\dfrac{-3}{2}\Rightarrow x=\dfrac{21}{17}\)
Vậy \(x=\dfrac{21}{17}\)
c) \(\dfrac{5}{8}+\dfrac{1}{3}:x=\dfrac{1}{2}\)
\(\Rightarrow\dfrac{1}{3}:x=\dfrac{-1}{8}\Rightarrow x=\dfrac{-8}{3}\)
Vậy \(x=\dfrac{-8}{3}\)
d) \(\dfrac{-5}{6}+\dfrac{8}{3}+\dfrac{-29}{6}< x< \dfrac{-1}{2}+2+\dfrac{5}{2}\)
\(\Rightarrow-3< x< 4\)
\(\Rightarrow x\in\left\{-2;-1;0;1;2;3\right\}\) vì x thuộc Z
Vậy \(\Rightarrow x\in\left\{-2;-1;0;1;2;3\right\}\)
Các bạn ơi giúp mk trả lời mấy câu hỏi này với mk đang cần rất gấp ngay bây giờ đây nè!!!!!
