how do u sovle

Question

3a-1 & 2a-1?? 

Answer 1

3a -1 & 2a -1 = 5a -2 (if you mean (3a-1)+(2a-1))

but PEMDAS is the order of operations where addition comes before subtraction, A before S, the last 2 letters of PEMDAS

so, 3a-1 + 2a -1 = 3a -(1+2a) -1 = 3a-1-2a-1 = a-2

odds are though, you probably meant the first problem & solution 5a-2