Translate to an Alegebraic expression

Question

Twice d. my answer is 2-d
is this right.
-(y+48)=y-48 is this right

Answer 1

2d
the second is wrong.
-y-48 both y and 48 were postive, multiplied by a negative.

Answer 2

-(y+48)=y+48 is this right.
4(n+)=4n+4 is this right.

F=M+V/2 I do not how to work this.

Answer 3

F= m+v/2 I do not how to work this problem could someone help me
please