Question

Daca a=2n+3 si b=3n+6 atunci 5/(a+b+1) n £N

Answer 1

a+b+1 = 2n+3+3n+6+1 = 5n+10 = 5(n+2)
5/a+b+1 = 5/ 5(n+2) = 1/ n+2

Answer 2

$a=2n+3$

$b=3n+6$

⇒$\frac{5}{a+b+1} = \frac{5}{2n+3+3n+6+1} = \frac{5}{5n+10}$ $= \frac{1}{n+2}$