Write each fraction as an expression using exponent other than -1

Bring the fraction a/a-4 to a denominator of 16-a^2

These tables represent a quadratic function with a vertex at (0, -1). what is the average rate of change for the interval from x = 9 to x = 10?

The vertices of a triangle are a(7.5), b(4,2), and c19. 2). what is