Question

(3 phần 4 + X ) . -2 phần 7= 4 phần 21

TỰ LUẬN

Answer 1

=>x+3/4=-2/3

=>x=-2/3-3/4=-17/12

Answer 2

x=17/12

Answer 3

\(\left(\dfrac{3}{4}+x\right)\times\dfrac{-2}{7}=\dfrac{4}{21}\)

\(\Leftrightarrow\left(\dfrac{3}{4}+x\right)=\dfrac{4}{21}:\dfrac{-2}{7}\)

\(\Leftrightarrow\dfrac{3}{4}+x=-\dfrac{2}{3}\)

\(\Leftrightarrow x=-\dfrac{2}{3}-\dfrac{3}{4}\)

\(\Leftrightarrow x=-\dfrac{17}{12}\)