Which proportion is equivalent to a/b = c/d
a. a/c = b/d
b. a/d = b/c
c. a/c = d/b
d. a+b/h = c+b/d

Find the volume of the described solid.the solid lies between planes perpendicular to the x-axis at x = 0 and x=7. the cross sectionsperpendicular to the x-axis between these planes are squares whose bases run from the parabolay=-31x to the parabola y = 30/x.a) 441b) 147c) 864d) 882