Help me solve this test :)

Two rigid transformations are used to map abc to qrs. the first is a translation of vertex b to vertex r. what is the second transformation? a reflection across the line containing ab a rotation about point b a reflection across the line containing cb a rotation about point c

Let f(x) = 3 − x . find the average rate of change of f(x) from x = a to x = a + h and simplify your answer so that no single factor of h is left in the denominator.

What is the value of x when x + 7 = 21?