Subtracting goal value from last filled entry

[ciacaete]

Hi, I'm a beginner in Power BI and DAX functions, and I'm trying to subtract the column "Meta Horária" and "Entrada Caeté" like this: 

Diferença Entrada de Cana e Meta = MAX(Planilha1[ENTRADA_CANA])- MAX(Planilha1[META_ACUMULADA_CANA])

 I've also tried like this 

Diferença Entrada de Cana e Meta = MAX(Planilha1[ENTRADA_CANA])- SUM(Planilha1[META_ACUMULADA_CANA])

But none have returned the value I wish for, I'd like to have both values as indicated in the image in the subtraction yet, I don't see how I'm able to do it, the expected value would be "809-1260=-451". How can I do it?

[jgeddes]

You should be able to use a calculated column to get the desired result.

Diferenca Entrada de Cana e Meta =

Planilha1[Entrada Cana] - Planilha1[Meta__Acumulada_Cana]

[ciacaete]

Thank you! but now I've encoutered a new problem, how can I make that it only executes the function if I have a value and if I don't, leave it blank? 

[jgeddes · Accepted solution]

Diferenca Entrada de Cana e Meta =

IF(
ISBLANK(Planilha1[Entrada Cana])
BLANK(),
Planilha1[Entrada Cana], - Planilha1[Meta__Acumulada_Cana]
)

Should do it.