Answer:
a) 2(a+b)
Explanation:
the sum of 2 numbers (or more) is always addition
so the sum of a and b would be (a+b)
then, 2 times of a and b;
2(a+b)
^the times sign between the bracket and the 2 isnt needed, whenever there is a bracket and a number next to it, it is automatically a multiplication.