Anybody help me please

Atriangle with all sides of equal length is a/an triangle. a. right b. scalene c. equilateral d. isosceles

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

What is the solution to this system of equations? y= 2x - 3.5 x - 2y = -14