Question

Which expression is prime?


A)
x^2 - 9

B)
1 - 9x^2

C)
2a^2 - 25

D)
4x^2 - 9

Answer 1

Hint look for expressions of the type a^2 - b^2 They can be factored

Answer 2

eg 9 - x^2 = (3-x)(3+x) so thats not prime

Answer 3

no
1 - 9x^2 = ( 1- 3x)(1 + 3x)

Answer 4

which of the functions does not contain 2 perfect squares?

Answer 5

there's just one term not a perfect square

Answer 6

umm.... c

Answer 7

right - 2a^2 is not a perfect square

C is prime

Answer 8

thanks!

Answer 9

its not the same type as the other 3 ( i e differnce of 2 squares) and there is no common factor for 2a^2 and 25.

Answer 10

http://usatestprep.com/modules/gallery/files/5/508/508.gif

and is this AAS?