How to solve a problem including percent increase and decrease

Linet passes through (4.5) and is perpendicular to the line shown on the condirate grid.what is the equation of line t in standard form?

Express the following as a function of a single angle. cos(60) cos(-20) - sin(60) sin(-20)

The area of a rectangle is 10 cm^2. one side of the rectangle is x cm. express the perimeter of the rectangle in terms of x and show that this rectangle cannot have a perimeter of 12 cm. the perimeter of the rectangle in terms of x is __ cm