Find the exact values of the following, giving your answers as fractions

Find the area of the triangle formed by the origin and the points of intersection of parabolas y=−3x^2+20 and y=x^2−16.

What is the length of the midsegment of a trapezoid with bases of length 15 and 25 ?

What is the value of the discriminant, b2 ? 4ac, for the quadratic equation 0 = x2 ? 4x + 5, and what does it mean about the number of real solutions the equation has?