Could someone me with these two problems?

For the first one:
What you would do is Add each item separately. 
$3.20 for the sandwich *plus* $0.88 for the chips *plus* $0.99 for the drink.
$5.07 would be the price for everything separate.
So which would be the better deal for Anthony?

For the second one: 
you are looking for which number is farther away from 5
You always have to look at 0 first (try drawing your own number line first)
Your answer would be -5.14 because 5 to 11 is closer than 5 to -5.14

Hope ive helped.
Good luck