How to get answer by Mimiwhatsup:
[tex]x^2-12x+36\\Break\:the\:expression\:into\:groups\\=\left(x^2-6x\right)+\left(-6x+36\right)\\\mathrm{Factor\:out\:}x\mathrm{\:from\:}x^2-6x\mathrm{:\quad }x\left(x-6\right)\\\mathrm{Factor\:out\:}-6\mathrm{\:from\:}-6x+36\mathrm{:\quad }-6\left(x-6\right)\\=x\left(x-6\right)-6\left(x-6\right)\\\mathrm{Factor\:out\:common\:term\:}\left(x-6\right)\\=\left(x-6\right)\left(x-6\right)\\Refine\\Answer: \left(x-6\right)^2[/tex]
