[tex]1\dfrac{3}{12}=1\dfrac{3:3}{12:3}=1\dfrac{1}{4}\\\\36\dfrac{9}{12}=36\dfrac{9:3}{12:3}=36\dfrac{3}{4}[/tex]
[tex]1\dfrac{3}{12}+36\dfrac{9}{12}=1\dfrac{1}{4}+36\dfrac{3}{4}=(1+36)+\left(\dfrac{1}{4}+\dfrac{3}{4}\right)=37\dfrac{1+3}{4}=37\dfrac{4}{4}=37+1=38[/tex]
