Am trying to find the value of r
1/r + 2/1-r = 4/r^2

Using the quadratic formula find the zeros of the given polynomial -5x^2+3x-11

In the diagram below? p is circumscribed about quadrilateral abcd. what is the value of x

Candy lives in the center of town. her friend darlene lives 28 miles to the east and her friend dana lives 21 miles north. approximately how far do dana and darline live apart ?