Let A and B be groups, and consider the product group G=A x
B.
(a) Prove that N={(ea,b) E A x B| b E B} is a
subgroup.
(b) Prove that N is isomorphic to B
(c) Prove that N is a normal subgroup of G
(d) Prove that G|N is isomorphic to A
Let G be a group. For each x ∈ G and a,b ∈ Z+
a) prove that xa+b = xaxb
b) prove that (xa)-1 = x-a
c) establish part a) for arbitrary integers a and b in Z
(positive, negative or zero)
Prove that an abelian group G of order 2000 is the direct
product PxQ where P is the Sylow-2 subgroup of G, and Q the Sylow-5
subgroup of G. (So order of P=16 and order or Q=125).
prove that where a,b,c,d,e are real numbers with (a) not equal
to zero. if this linear equation ax+by=c has the same solution set
as this one : ax+dy=e, then they are the same equation.