Please help me on 8 and 11.

1.) 2x + y = 3 2.) x - 2y = -1 if equation 1 is multiplied by 2 and then the equations are added, the result is a.3x = 2 b.3x = 5 c.5x = 5

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

Identify the polynomial. a2b - cd3 a.monomial b.binomial c.trinomial d.four-term polynomial e.five-term polynomial