Find all values of b that will make the polynomial a perfect square trinomial: 25z^2 + bz + 9

Question

I need all the values that will make the polynomial a perfect square trinomial, preferably listed in the correct order.

Answer 1

25z² + bz + 9 = (5z + 3)(5z + 3) = (5z - 3)(5z - 3)

 

 

If you only look at the outer and inner terms, you get

 

15z + 15z = 30z or -15z - 15z = -30z

 

Therefore, b = -30 or b = 30

Answer 2

25z² + bz + 9

(5z)² + bz + 3²

b = 2(5)(3)

 

Just like the last time I solve it.