Q$9.$Help me do thid please. Explain every step

$//8$ marks

An engineer has a signed byte $x=0x84.$ They need to add it to a signed halfword $(16$ bit$)$ operand $y=034(0$x$0034$ to show all nibbles, but leading os are not written, so we will not write them in future, you are welcome to confirm if and when unclear$).$ The result is saved in a signed halfword variable z $.$

a$.$ What will the value of $z$ be in hex and in decimal $?$ Please show all steps of calculation.