Find all Values of b that will make the polynomial a perfect square trinomial.
25z^2+bz+36
Please write out how to do this so I can see the steps of what I am doing wrong. thank you!

Respuesta :

Answer:

There are two solutions for [tex]b[/tex]: [tex]b = + 30\cdot z[/tex], [tex]b = -30\cdot z[/tex]

Step-by-step explanation:

By Algebra, we know that a polynomial is a perfect square trinomial if it is of the form:

[tex]a^{2} + 2\cdot a \cdot c + c^{2} = (a + c)^{2}[/tex] (1)

By direct comparison, we have the following system:

[tex]a^{2} = 25\cdot z^{2}[/tex], [tex]c^{2} = 36[/tex], [tex]2\cdot a \cdot c = b[/tex].

There are two possible solutions for [tex]b[/tex]:

1) [tex]a = \pm 5\cdot z[/tex], [tex]c = \pm 6[/tex], [tex]b = + 30\cdot z[/tex]

2) [tex]a = \pm 5\cdot z[/tex], [tex]c = \mp 6[/tex], [tex]b = -30\cdot z[/tex]