1- Subtract (7a^2 - 3a) - (5a^2 - 5a)

a) 2a^2 + 2a
b) 2a^2 - 8a**
c) 12a^2 - 8a
d) 12a^2 + 2a

2- Is x(4x^2 - 16) completely factored? If not, how else can it be factored?
a) no; 4 can be factored from each term of the binomial AND the resulting binomial is a difference of two squares that factors into two binomials.
b) no; the binomial is a difference of two squares and can be factored into two binomials.
c) no; 4 can be factored from each term of the binomial.**
d) yes; the polynomial is completely factored.

3- Determine whether p^2 - 40 is a difference of two squares. If so, choose the correct factoring.
a) yes; (x - 20)^2
b) yes; (x - 10)^4
c) yes; (x + 4) (x - 10)**
d) no

PLEASE HELP ASAP :)

3 answers

0 for 3

1 ... distributing the minus ... 7a^2 - 3a - 5a^2 + 5a
... combine like terms

2 ... after factoring out the 4 , the difference of two squares is remaining

3 ... 40 is not a perfect square (not a whole number root)
1. nope
(7a^2 - 3a) - (5a^2 - 5a)
= 7a^2 - 3a - 5a^2 + 5a
=
2. nope
I see a common factor followed by a difference of squares in
4x^2 - 16
= 4(x^2 - 4)
= 4(x-2)(x+2) , don't forget the x in front

3. 40 would have to be a perfect square. It is not