Expand the following: \begin{align} (x+1)^2 &= \cssId{Step1}{(x+1)(x+1)} \\[3px] &\cssId{Step2}{{} = x(x+1) + 1(x+1)} \\[3px] &\cssId{Step3}{{} = (x^2+x) + (x+1)} \\[3px] &\cssId{Step4}{{} = x^2 + (x + x) + 1} \\[3px] &\cssId{Step5}{{} = x^2 + 2x + 1} \end{align}