Parallelogram ABCD is rotated to create image A'B'C'D'. On a coordinate plane, 2 parallelograms are shown. The first parallelogram has points A (2, 5), B (5, 4), C (5, 2), D (2, 3). The second parallelogram has points A prime (5, negative 2), B prime (4, negative 5), C prime (2, negative 5), D prime (3, negative 2).
Which rule describes the transformation?

(x, y) → (y, –x)
(x, y) → (–y, x)
(x, y) → (–x, –y)
(x, y) → (x, –y)

Each person in an it department of 25 people works on at least one of 3 major projects: system security, program implementation, platform development. 10 people work on system security, 13 work on program implementation, and 12 work on platform development. 4 people work on system security and platform development, 5 people work on program implementation and platform development, and 2 people work on all three projects. how many people work on system security and program implementation?