Find the area under the graph offover the interval [- 1,3]. 2 x51 f(x)= x +1 2x x>1 The area is . (Simplify your answer.) Find the area of the region bounded by the graphs of the given equations. y = 8, y= 1x , x=0 The area of the region is . (Simplify your answer.)-1600x Arm has the marginal-demand function D'(x) = 2, where D(x) is the number of units sold at x dollars per unit. Find the demand function given that D = 15,000 when x = $4 per unit. 25-x The demand function is D(x) =