Resolução desafio

1 - total movel 30 dias = 
var DataAtual = MAX(Tb_Calendario[Date])

RETURN
if(
    COUNTROWS(Tb_ItensNotas) > 0, 
    CALCULATE(
        [Total Vendas],
        DATESBETWEEN(
        Tb_Calendario[Date],
        DataAtual -30,
        DataAtual
    )
    )
)



2 - total movel 30 dias LY = 
 
var DataAtual = MAX(Tb_Calendario[Date])

RETURN
if(
    COUNTROWS(Tb_ItensNotas) > 0, 
    CALCULATE(
        [Total Vendas Ano Anterior],
        DATESBETWEEN(
        Tb_Calendario[Date],
        DataAtual -30,
        DataAtual
    )
    )
)



3 - Media Movel = 
var DataAtual = MAX(Tb_Calendario[Date])

RETURN
if(
    COUNTROWS(Tb_ItensNotas) > 0, 
AVERAGEX(
    DATESBETWEEN(
        Tb_Calendario[Date],
        DataAtual -30,
        DataAtual
    ),
    [Total Vendas]
)
)





4 - media movel ly = 
var DataAtual = MAX(Tb_Calendario[Date])

RETURN 
if(
    COUNTROWS(Tb_ItensNotas) > 0, 
AVERAGEX(

    DATESBETWEEN(
        Tb_Calendario[Date],
        DataAtual -30,
        DataAtual
    ),
    [Total Vendas Ano Anterior]
)
)