Determine which polynomial is a perfect square trinomial.
4x2 − 12x + 9
16x2 + 24x − 9
4a2 − 10a + 25
36b2 − 24b − 16

 Trinomial Ax^2 + Bx + C is perfect square if: 
A > 0 
C > 0 
B = ±2√A√C 

36b^2 − 24b − 16
 C < 0 

4a^2 − 10a + 25
 2√A√C = 2*2*5 = 20,
 B = −10 

16x^2 + 24x − 9
 not perfect square,
 C < 0 

4x^2 − 12x + 9
perfect square:
A>0,
C>0,
2√A√C
= 2*2*3
= 12
 = -B 
= (2x − 3)^2
hope this helps