Question

Simplify the following expression.
2a+3-9b-a-7

Answer 1

a-9b-4

Answer 2

just combining like terms,
2a- a = a
3-7= -4
-9b=-9b

Answer 3

you cant mix a's with b's

Answer 4

and you cant add integers( ie 3 and - 7) with the a's or b's

Answer 5

so, to sum up,
start from left to right, the first term you run into is 2a, then you pass by +3 -9b and run into -a

Answer 6

so what is 2a - a?