How many possible pairs of number factors does c have in the fallowing trinomial?
x^2+bx+36

X^2 + ( m + n )x + m*n = ( x + m )( x + n ) ;
We have m*n = 36 and m + n = b ;
1*36 = 36 ; m = 1 ; n = 36 ; the factors are ( x + 1 ) , ( x + 36 )
2*18 = 36 ; m = 2 ; n = 18 ; the factors are ( x + 2 ) , ( x + 18 )
3*12 = 36 ; m = 3 ; n = 12 ; the factors are ( x + 3 ) , ( x + 12 )
4*9 = 36 ; m = 4 ; n = 9 ;    the factors are ( x + 4 ) , ( x + 9 )
6*6 = 36 ; m = 6 ; n = 6 ;    the factors are ( x + 6 ) , ( x + 6 )
There are 5 pairs of number factors.