Question

which one is unfactorable?
a) 25x^2-y^2
b) 21x+28
c) x^2+3x+4
d) x^6-1

Answer 1

a) cause it involves 2 different variables and hence there is not question about factorising it.... factorising is done for similar variables...

Answer 2

Hi brackett ,was just wondering about smaller factors such as:
a)25x(x)-y(y)
b) 7(3x+4)
c)x(x+3)+4
d)x(x^5)-1
what do you think?