[tex]\it \bf 1.\ \it 5^4-5^3=5^2(5^2-5)=25\cdot20=500\\ \\ \bf 2.\ \it\dfrac{x}{5}=\dfrac{\ 8^{(4}}{20} \Rightarrow \dfrac{x}{5}=\dfrac{2}{5} \Rightarrow x=2\\ \\ \bf 3.\ \it n:11=a\ \ rest\ 1 \Rightarrow n=11a+1\\ \\ n \ este\ minim\ pentru \ a=0,\ adic\breve a\ n=11\cdot0+1 \Rightarrow n=1\\ \\ \bf 4.\ \ \it 0,24m^3=0,24\cdot1000dm^3=240dm^3=240\ell\\ \\ \bf 5.\ \ \it \mathcal{A}=\ell^2=\Big(\dfrac{\mathcal{P}}{4}\Big)^2= \Big(\dfrac{1,2}{4}\Big)^2=0,3^2=0,09m^2[/tex]
