Q:

Which trinomials are perfect square trinomials? Select each correct answer. A) m^2+10m+100 B) m^2+10m+25 C) m^2+24m+144 D) m^2+36m+60

Accepted Solution

A:
a perfect square trinomial can be factored into the form
[tex](a+b)^2[/tex]
the expansion is
[tex]a^2+2ab+b^2[/tex]
so if we say that a=m then
[tex](m+b)^2=m^2+2mb+b^2[/tex]
basically, if you take the coefient (number part) of the 2mb term and divide it by 2 and square it, you should get the last term

(coefient is the number part, like in 4m, 4 is the coefient)

A.
[tex]m^2+10m+100[/tex]
10m is the 2mb term
10 is the coefient, 10/2=5, 5^2=25, 25β‰ 100, so not a perfect square trinomial

B.
[tex]m^2+10m+25[/tex]
as from before, 10 is coefient, 10/2=5, 5^2=25, 25=25, yep, this is perfect square trinomial

C.
[tex]m^2+24m+144[/tex]
24m is the 2mb term, 24 is coefient, 24/2=12, 12^2=144, 144=144, yep this is a perfect square trinomail

D.
[tex]m^2+36m+60[/tex]
36m is the 2mb term, 36 is the coefient, 36/2=18, 18^2=324, 324β‰ 60, so not a perfect square trinomial



answers are B and C