Answer:
The answer is 40a+14c
Step-by-step explanation:
Step 1: Open the brackets
7a-9c+12a+33c+21a-10c
Step 2: Group all the like terms
Like terms are terms with similar variables, for example;
(7a, 12a, 21a) are all like terms since they have a common variable (a)
(-9c, 33c,-10c) are also like terms since they have a common variable (c)
Step 2: Solve
(7a+12a+21a)+(33c-10c-9c)=40a+14c
The answer is 40a+14c
