Question

Tìm x biết:

1,2:(−2,8)=x:21

Đáp số: x= ???

Answer 1

\(\dfrac{1.2}{-2.8}=\dfrac{x}{21}\)

\(=>x=1.2\cdot21:-2.8=-9\)

Vậy x=-9

Answer 2

1.2\(−2.8)=𝑥\21

=>𝑥=−9

Answer 3

\(1.2:\left(-2.8\right)=x:21\)

\(\Leftrightarrow x=\dfrac{1.2}{\left(-2.8\right)}\cdot21=-9\)

Answer 4

Ta có: 1.2:(-2.8)=x:21

\(\Leftrightarrow\dfrac{x}{21}=\dfrac{-3}{7}\)

\(\Leftrightarrow x=\dfrac{-3\cdot21}{7}=-3\cdot3=-9\)

Vậy: x=-9