a,x.200=2,456+6,544
x.200=9
x =9:200
x =0,045
x =4,5%
b,0,64:x=4-0,8
0,64 :x=3,2
x=0,64:3,2
x=0,2
x=20%
\(a.200x=2,456+6,544\)
\(\Rightarrow200x=9\)
\(\Rightarrow x=\frac{9}{200}=\frac{4,5}{100}\)
\(\Rightarrow x=4,5\%\)
\(b.0,64\div x=4-0,8\)
\(\Rightarrow0,64\div x=3,2\)
\(\Rightarrow x=\frac{0,64}{3,2}\)
\(\Rightarrow x=0,2\)
\(\Rightarrow x=20\%\)