Câu hỏi của Mai gia bảo

Question

bài 3: Tìm y

a) $\dfrac{1}{2}$ : y x $\dfrac{3}{5}=\dfrac{4}{3}+\dfrac{3}{4}$       b) $\dfrac{4}{3}-\dfrac{1}{2}$ x y $=1$      c) $\dfrac{1}{4}+y$ : $\dfrac{1}{3}=\dfrac{5}{6}$

HT.Phong (9A5) · Accepted Answer

a) $\dfrac{1}{2}:y\times\dfrac{3}{5}=\dfrac{4}{3}+\dfrac{3}{4}$

$\dfrac{1}{2}:y\times\dfrac{3}{5}=\dfrac{25}{12}$

$\dfrac{1}{2}:y=\dfrac{25}{12}:\dfrac{3}{5}$

$\dfrac{1}{2}:y=\dfrac{125}{36}$

$y=\dfrac{1}{2}:\dfrac{125}{36}$

$y=\dfrac{18}{125}$

b) $\dfrac{4}{3}-\dfrac{1}{2}\times y=1$

$\dfrac{1}{2}\times y=\dfrac{4}{3}-1$

$\dfrac{1}{2}\times y=\dfrac{1}{3}$

$y=\dfrac{1}{3}:\dfrac{1}{2}$

$y=\dfrac{2}{3}$

c) $\dfrac{1}{4}+y:\dfrac{1}{3}=\dfrac{5}{6}$

$y:\dfrac{1}{3}=\dfrac{5}{6}-\dfrac{1}{4}$

$y:\dfrac{1}{3}=\dfrac{7}{12}$

$y=\dfrac{7}{12}\cdot\dfrac{1}{3}$

$y=\dfrac{7}{36}$Câu trả lời: a) $\dfrac{1}{2}:y\times\dfrac{3}{5}=\dfrac{4}{3}+\dfrac{3}{4}$