Question

Answer 1

Bài 7:

a: \(\Leftrightarrow\dfrac{39}{7}:x=13\)

nên \(x=\dfrac{39}{7}:13=\dfrac{39}{7}\cdot\dfrac{1}{13}=\dfrac{3}{7}\)

b: \(\Leftrightarrow x\cdot\dfrac{1}{6}=\dfrac{5}{12}\)

hay x=5/2

c: \(\Leftrightarrow x=\dfrac{13}{12}\cdot\dfrac{46}{15}=\dfrac{299}{90}\)

d: \(\Leftrightarrow x\cdot\left(\dfrac{3}{4}+\dfrac{2}{5}\right)=1\)

\(\Leftrightarrow x\cdot\dfrac{23}{20}=1\)

hay x=20/23