\(\frac{-x}{21}=\frac{20}{7}\)
\(\Rightarrow-x.7=21.20\)
\(\Rightarrow-x.7=420\)
\(\Rightarrow-x=420:7\)
\(\Rightarrow-x=-60\)
\(\frac{-x}{21}=\frac{20}{7}\)
\(\Rightarrow-x.7=20.21\)
\(\Rightarrow-7x=420\)
\(\Rightarrow x=420:-7\)
\(\Rightarrow x=-60\)
Vậy \(x=-60\)
Chúc bạn học tốt !!!
\(\frac{-x}{21}=\frac{20}{7}\)
\(\Leftrightarrow-x.7=20.21\)
\(\Leftrightarrow-x.7=210\)
\(\Leftrightarrow-x=30\)
\(\Leftrightarrow x=30\)
=> -x.7=21.20
=> -x.7 = 420
=> -x = 420 : 7
=>-x = 60
=> x = -60
Vậy x = -60
