How to sum values or subtraction in same measurement?

Hi for all,
I have measurement with structure:

image

image

And tag variavel

My select:
SELECT "v1","v2" FROM (SELECT last("value") as "v1" FROM "industriaopc" WHERE "variavel" = 'a110_003_0_FY_DACA_PV'), (SELECT last("value") as "v2" FROM "industriaopc" WHERE "variavel" = 'a110_001_0_FIC_DACA_PV')

Produces two lines v1 and v2:

image

How to use sum or subtraction or multi in v1 and v2?

This select:
SELECT ("v1"+"v2") FROM (SELECT last("value") as "v1" FROM "industriaopc" WHERE "variavel" = 'a110_003_0_FY_DACA_PV'), (SELECT last("value") as "v2" FROM "industriaopc" WHERE "variavel" = 'a110_001_0_FIC_DACA_PV')

Reproduces:

image