You can drop the parentheses around 4 - 5y. (4 - 5y) is the same as 4 - 5y.
But you must expand (multiply out) -2(3.5y - 8). The result is
-7y + 16 Here we are applying the Distributive Property of Multiplication.
Now combine 4 - 5y and - 7y + 16. Result: -12y + 20 (answer)
If you need clarification here, please ask!