Arrange the steps from start to finish to factor this expressions using the grouping method

Use the four functions below for this question. compare and contrast these four functions using complete sentences focus on the slope and y- intercept first, and then on any additional properties of each function

What is the axis of symmetry of the function f(x)=-(x+ 9)(x-21)

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.