Write a system of equations to model each situation, and solve for the values of the appropriate variables.
a. The perimeter of a rectangle is 44 cm. Its length is 2 cm more than twice its width.
b. The perimeter of an isosceles triangle is 40 cm. The base length is 2 cm less than the length of a leg of the triangle.
c. The Fahrenheit reading on a dual thermometer is 0.4 degrees less than three times the Celsius reading.