\(\dfrac{7011}{25}:\left(x-42.6\right).15=13\)
\(\Rightarrow\dfrac{7011}{\dfrac{25}{\left(x-42,6\right)}}.0,15=13\)
\(\Rightarrow\dfrac{280,44}{\left(x-42,6\right)}.0,15=13\)
\(x-\left(280,44-42,6\right)\)
\(x=237.8+86,7\)
\(x=324,54\)
\(\)Vậy x=324,54
b.
\(7,2-\left(x+3,75:2,1\right):1,9=5,2\)
\(\Rightarrow7,2+\dfrac{-\left(x-\dfrac{3,75}{2,1}\right)}{1,9}=5,2\)
\(7,2+\dfrac{-\left(x-1,8\right)}{1,9}=5,2\)