a) thay \(x=3;y=2\) vào ta có : \(2x^2-3xy+x=2.3^2-3.3.2+3=2.9-18+3=18-18+3=3\)
b) ta có : \(x\left(x-y\right)+y\left(y-x\right)\Leftrightarrow x\left(x-y\right)-y\left(x-y\right)=\left(x-y\right)\left(x-y\right)=\left(x-y\right)^2\)
thay \(x=53;y=3\) vào ta có : \(\left(53-3\right)^2=\left(50\right)^2=2500\)