Question

Faceti va rog mult 11

Answer 1

Salut,

$n=\overline{a4}\cdot\overline{a6}+1=(10a+4)(10a+6)+1=100a^2+60a+40a+24+1=\\=100a^2+100a+25=(10a)^2+2\cdot 10a\cdot 5+5^2=(10a+5)^2,\ care\ este\ p\breve{a}trat\ perfect.$

Green eyes.

Answer 2

[tex]\it n = \overline{a4} \cdot \overline{a6} +1 = \overline{a4} \cdot( \overline{a4}+2) +1 \\\;\\ Notez\ \overline{a4} =x, \ iar\ n\ devine: \\\;\\ n = x(x+2) +1 = x^2+2x+1 = (x+1)^2[/tex]

Revenind asupra notației, obținem:

$\it n = (\overline{a4}+1)^2 = (10a+4+1)^2 =(10a+5)^2$