Consider T:R$5$RTand S:R$^7->$R$^8$ with T$($x$)=$ Ax and S$($x$=$ Bx$.$

$($a$)$ If SoT:R Rm then m$=$

$($b$)$ The matrix associated with $ $$ T is $($circle correct response$)$:

$$ AB

$$ BA

$$ something else