a) [tex]\frac{b+5}{3} =0/*3\\=> b+5=0 => b=-5[/tex]
b) [tex]\frac{x(x+3)}{x-1} =0/* (x-1)\\x( x+3)=0 => x_{1} =0, x_{2} =-3[/tex]
c) [tex]\frac{(n-1)(2n+8)}{n(n+3)} =0/* n(n+3)\\=> (n-1)(2n+8)=0\\=> n_{1} -1=0 => n_{1}=1 \\=> 2n_{2} +8=0 => 2n_{2} =-8 => n_{2} =-4[/tex]
