Bob has some 10 lb weights and some 3 lb weights. together, all his weights add up to 50 lbs. if x represents the number of 3 lb weights and y represents the number of 10 lb weights, which equation can be used to find the number of each type of weight bob has?

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