Question 965893
a(x+a)^2-4x^2
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{{{a(x+a)^2-4x^2=a(x^2+2ax+a^2)-4x^2}}}
{{{a(x+a)^2-4x^2=(ax^2+2a^2x+a^3)-4x^2}}}
{{{a(x+a)^2-4x^2=(a-4)x^2+2a^2x+a^3}}}