I can tell that you are really frustrated since your worksheet is really crumpled XD I get you .
Part A:Expression 1 and 4
workings :
expression 1 : 9+5x-5+3x = 5x+3x+9-5(arrange like terms )
=8x+4
expression 4: 4(1+2x) (expand) = 4+8x
since 8x+4 is the same as 4+8x , expression 1 &4 is equal
PART B:EXPRESSION 3
given expression : 2x+9-x+3 =x+12
since expression 3 is x +12, expression 3 is equivalent to the expression given