12a2b + 6a = 6a(2ab + 1)
12a- 6a + a = 7a Since they all have the same variable, you can simply add and subtract 12-6 = 6 6+1 = 7
4a+8a = 12a 12a divided by 2 = 6a
It is 20a - 5b - 9.
21a - 6a
12a²
12a
12a^2
6a
It is not clear whether the question is 3a + 4a + 5a + 6a^3 which would be 12a + 6a^3 or 3a + 4a + 5a + (6a)^3 = 12a + 216a^3 or (3a + 4a + 5a + 6a)^3 = 5832*a^3 But none of these really require summation notation!
a+6a+a=8a
6a plus 18b = 24