Hi,
I am having trouble with this question so it would be really nice if anyone could provide some help.
Let $$\phi: G \to G'$$ be a group homomorphism, and let $$H' \le G'$$ be a subgroup of G'.
a) Show that $$H=\phi^{-1}(H')$$ is a subgroup of G.
b) Now suppose H’ is a normal subgroup of...