Question

Va rog sa ma ajutați!​

Answer 1

 

$\displaystyle\bf\\ n=1+2+...+20+75:15\\\\1+2+...+20=\frac{20\times21}{2}=10\times21=\boxed{\bf210}\\\\75:5=\boxed{\bf15}\\\\n=1+2+...+20+75:15=210+15=\boxed{\boxed{\bf225=\bf15^2=pp}}$