HELP ME PLZ

1

Step-by-step explanation:

When solving an expression with different operations, we evaluate:

1. Brackets (This has to take the top priority in any expression with brackets, do the divisions and multiplications in the brackets first before the additions and subtractions if any)

2. Divisions and Multiplication (Do from left to right)

3. Addition and Subtraction (Do from left to right)

6 ÷ 2(1+2) = 6 ÷ 2(3)

                = 6 ÷ 6

                = 1

it is a. 4.2 because 7.6-3.4 gets the remaining length of 4.2. i might be wrong but i am pretty sure this is the answer.