64+(-80)-2

So we would do this like

64 + (-80) -2   

= 64 - 80 -2  ( out here we have put minus sign in 64+(-80)  becoz plus minus is equal to minus , if u still dont get it then i mean if there is a plus and a minus sign we would choose minus sign so now we will  solve this by steps)

= -16 -2    ( out here we had subtracted 64 and 80 but now we will add -16 and -2 as there are two minus signs here so we will have to do addition and also we will add minus sign to the answer)

= -18    ANSWER

i hope u have understood by now but if not then pls be free to ask!

i hope this helps!

And i forgot one thing, we have to open brackets also on the first step!