Why do the symbols at right not constitute an equation

How to choose the sign of the radical in the denominator of the formula for the distance from a point to a line.

Robin spent 25% more time on his research project than he had planned he’s been an extra h ours on the project which of the following expressions could represent the number of hours rob actually spent on the project

What is the domain of the step function f(x)=[2x]-1?