a. functie descrescatoare f( -1 ) ≥ f( 3/2 )
m +1 - 3m - 5 + 2m +3 ≥ 9m/4 + 9/4 + 9m/2 + 15 /2 +2m +3
-2m -4 ≥ 27m /4+39/4
- 8m - 16 ≥ 27m + 39
27 m + 8m ≤ -16 -39
35 m ≤ - 55
7 m ≤ -11 ; m ≤ -11/7
b. f( -1) · f(1 ) < 0
( m+ 1 - 3m - 5 + 2m + 3 )· ( m+1+3m+5+2m+3 ) < 0
- ( 6m + 9 ) < 0
6m + 9 > 0 ; m > - 9/6 ; m > - 3/2