At a landfill site, a hole in the shape of a rectangular prism is to be dug out. The area of the rectangular cross-section measures $\left(5y+8\right)$(5y+8) square metres and the volume of the hole is to be $5y^2+3y-8$5y2+3y−8 cubic metres such that $\left(5y+8\right)\times\text{depth }=5y^2+3y-8$(5y+8)×depth =5y2+3y−8. Find the expression for the depth of the hole