I don’t get it what do I do to solve ?

Including 6% sales tax, an inn charges $135.68 per night. find the inns nightly cost

Helll ! 1,400 tons of wheat of two different varieties was delivered to the silo. when processing one variety, there was 2% of waste and 3% during the processing of the second variety of wheat. after the processing, the amount of remaining wheat was 1,364 tons. how many tons of each variety of wheat was delivered to the silo?

Which is the focus of a parabola with equation y2=4x