36×54+39×28+36×24=36*54+36*28+3*28+36*24=36*（54+28+24）+84=36*106+84=3816+84=3900
36×54+39×28+36×24=36×（54+24）+39×28=36x39x2+39×28=39x（72+28）=39x100=3900
