It’s on solving systems of equations... can anyone help me pls

At a sale this week, a desk is being sold for $213. this is a 29% discount from the original price. what is the original price?

What is always true when two whole numbers are subtracted?

Gravel is being dumped from a conveyor belt at a rate of 25 ft3/min, and its coarseness is such that it forms a pile in the shape of a cone whose base diameter and height are always equal. how fast is the height of the pile increasing when the pile is 14 ft high? (round your answer to two decimal places.) ft/min