Shen rented a truck for one day. There was a base fee of

$16.99, and there was an additional charge of

88 cents for each mile driven. Shen had to pay $203.55

when he returned the truck. For how many miles did he drive the truck?

Ok so he had to pay (i'll say 17 because it's easier to type but understand it's 16.99) 17 dollars up front, and he paid 0.88x, x being miles driven. This means for how many miles he's driven, the equation would look like 17 + 0.88x. Set this equal to 203.55 to find out how many miles he drove. Solving this you get 212 miles.