Expand: (a+b)(c+d)(a + b)(c + d)(a+b)(c+d).
ac+ad+bc+bdac + ad + bc + bdac+ad+bc+bd
ac+bdac + bdac+bd
a2+2ab+b2a^2 + 2ab + b^2a2+2ab+b2
ac+ad+bac + ad + bac+ad+b