Let

$20$f$($x$)$dx$=15,30$f$($x$)$dx$=2,20$g$($x$)$dx$=8,32$g$($x$)$dx$=14,$

Use these values to evaluate the given definite integrals.

a$)20($f$($x$)+$g$($x$))$dx$=$

b$)30($f$($x$)$g$($x$))$dx$=$

c$)32(3$f$($x$)+2$g$($x$))$dx$=$

d$)$ Find the value a such that $30($af$($x$)+$g$($x$))$dx$=0.$

a$=$