9A
That is at least a 1975 tractor. What model is it?
9a-99 = -90
It is the same as: 9a -4a = 5a
It is: 9a-a-a = 7a
9a - 8a = a
If: 9a = 18b Then: a = 2b
9a squared = 81a^2
9a verbal expression
9a+21 3(3a+7)
The simplified expression is -9a -9b.
There is nothing you can do to 9a + 5 without knowing the value of a.