\(a,\frac{x}{4}=\frac{21}{28}\Rightarrow\)\(x.28=4.21\Rightarrow x.28=84\Rightarrow x=84:28\Rightarrow\)\(x=3\)
\(\frac{x}{4}=\frac{21}{28}\)=> 28x = 4.21 = 84 => x = \(\frac{84}{28}=3\)
\(\frac{2x}{5}=\frac{-24}{10}\)=> 10.2x = 20x = -24.5 = -120 => x = \(\frac{-120}{20}=-6\)
\(b,\frac{2x}{5}=\frac{-24}{10}\Rightarrow\)\(\frac{2x}{5}=\frac{-12}{5}\Rightarrow2x=-12\Rightarrow x=-6\)
x = 4.21/28 = 3
b) 2x = -24.5/10 = -12
x = -12/2 = -6
a) <=> (4 . 21)/28=3
b) <=>x=[ (-24 .5)/10 ] /2