$2\mathrm{.}5$ Given the sematic rules in Fig $2,$ draw an annotated parse tree for the following expression.

$(3+4)(5+6)n$

Fig $2.$ Semantic rules

$2\mathrm{.}6$ Given Table $1,$ determine the costs of the following instruction sequences

$2\mathrm{.}6\mathrm{.}1LDR0,y$

$LDR1,z$

ADD $R0,R0,R1$

$STx,R0$

$2\mathrm{.}6\mathrm{.}2LDR0,$ I

MUL $R0,R0,8$

$LDR1,a(R0)$

$STb,R1$