Answer
(a) $T=250-2x$
(b) 190 tablets
(c) 125 days
Work Step by Step
(a) She starts with 250 tablets and takes 2 per day, so after $x$ days, the amount of tablets $T$ left would be:
$T=250-2x$
(b) Using the formula with $x=30$, we get:
$T=250-2*(30)=190$ tablets
(c) We set $T=0$ and solve for $x$:
$T=250-2x=0$
$250=2x$
$x=125$
So she will run out of tablets after 125 days.