Using summation and product notation, write mathematical expressions for the following pseudocode segments:

a$.$ integer $i,n$; real $v,x$ real array $(a_i{)}_{0n}$

$vlarr{a}_0$

for $i=1ton$

vlarrv$+x{a}_i$

end for

${?}^{a}b.$

integer $i,n$; real $v,x$

real array $(a_i{)}_0=n$

$vlarr{a}_n$

for $i=1ton$

$,$vlarrvx$+a_{n-i}$

end for

c$.$ integer $i,n$; real $v,x$ real array $(a_i{)}_{0\text{:}n}$

$vlarr{a}_0$

for $i=1ton$

vlarrvx$+a_i$

end for

d$.$ integer $i,n$; real $v,x,z$

real array $(a_i{)}_{0\text{:}n}$

$vlarr{a}_0$

zlarrx

$]=[1ton$