Describe how to use mental math to determine if a ratio is simplified

Consider the line y = -3/-2 x +6. find the equation of the line that is perpendicular to this line and passes through the point (-9,-3). find the equation of the line that is parallel to this line and passes through the point (-9,-3).

Each of the walls of a room with square dimensions has been built with two pieces of sheetrock, a smaller one and a larger one. the length of all the smaller ones is the same and is stored in the variable small. similarly, the length of all the larger ones is the same and is stored in the variable large. write a single expression whose value is the total area of this room. do not use any method invocations.

Find and simplify an expression for the area of five rows of x squares with side lengths of x centimeters.