\(\frac{x}{17}+\frac{19}{34}=2\frac{1}{2}\)
\(\Rightarrow\frac{2x}{34}+\frac{19}{34}=2\frac{1}{2}\)
\(\Rightarrow\frac{2x+19}{34}=2\frac{1}{2}\Rightarrow2x+19=34.2\frac{1}{2}\Rightarrow2x+19=85\Rightarrow2x=66\Rightarrow x=33\)
b) 30% * x + x =52
=> 3/10 * x + x=52
=> x * ( 3/10 + 1 ) = 52
=> x *1,3 = 52
=> x = 52 : 1,3 =40
\(\frac{x}{17}+\frac{19}{34}=2\frac{1}{2}=\frac{5}{2}\)
\(\frac{x}{17}=\frac{5}{2}-\frac{19}{34}\)
\(\frac{x}{17}=\frac{170}{68}-\frac{38}{68}\)
\(\frac{x}{17}=\frac{132}{68}\)
=>\(x.68=17.132\)
\(x.68=2244\)
\(x=2244:68\)
\(x=33\)
vậy x=33
dấu"." chính là phép nhân đó em!!!
chúc em học giỏi...
\(30\%.x+x=52\)
\(30\%.2x=52\)
\(\frac{30}{100}.2x=52\)
\(\frac{3}{10}.2x=52\)
\(2x=52:\frac{3}{10}=\frac{520}{3}\)
\(x=\frac{520}{3}:2=\frac{520}{6}\)
ko biết có đúng ko nữa!!!
