Can smby help me plz ?!

What is f(3) for the quadratic function f(x)= 2x^2+ + x - 12

Write the fraction 9/50 as a decimal if needed round to the nearest hundredth

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