$Q1$: What $is$ a linear program?

$a$

$TobeanLP,$ the model$s$ decision variables, constraints, and objective must have particular characteristics.

For each model below, report $if$ the following $is$ a linear program $or$ not, and briefly explain why. The decision variables are represented $byx1,x2.$

$b$

minx$1+10x2$

$s.t.$

$x1=1$

$x25$

$c$

maxx$1+x2$

$s.t.$

$3x1+x24$

$x1+x210$

$x1,x20,x1$ integer

$d$

min$3x22$

$s.t.$

$x14$

$x1,x20$

$e$

max$4x1+3x2$

$s.t.$

$|x1|+2x23$

$x1,x20$