How do you take a rectangle with a slanted left top corner and make two shapes without moving any lines?

There is a line with slope 1/a going through the point (a, a²). find the equation of the line perpendicular to this line at this point. (don’t let this problem intimidate you! solve the problem as you would if i’d given you specific values. just use variables instead.)

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

Solve this system of equations. 12x − 18y = 27 4x − 6y = 10