Question

Determine which polynomial is a perfect square trinomial.

49x2 - 28x + 16
9a2 - 30a + 25
25b2 - 45b - 81
16x2 - 24x - 9

Answer 1

ax^2 + bx + c

if this is a perfect square trinomial
then a and b will be perfect squares
and b will equal 2 * sqrt a *sqrt b

or if we have
a^2 - bx + c

the same applies to a and c
but - b will equal -2*sqrt a * sqrt b

Answer 2

trinomials with a negative sign c will not be perfect square trinomials

Answer 3

so is the answer b or c