The distance formula to find the length of the sides... opposite sides equal it could be a rectangle or parallelogram all sides equal, square or rhombus adjacent equal, kite and then the slope is used to check angles if the product of the 2 lines in -1 the lines are perpendicular (right angle) the slopes of 2 lines are the same the sides are parallel. Hope it helps.
9 (2x-5) =
Remember to look at words that indicate an operation is to take place (Eg: "times" (x) "less than" (-) "Twice x" (2x))
Hope this helps!
The real number would be 1.5 or 3/2 or 1 1/2