1 point Consider the set P3 = (ar3 + br2 + cr + d | a,b,c,dER)...
1 point Consider the set P3 = (ar3 + br2 + cr + d | a,b,c,dER) of polynomials of degree at most 3 with real coefficients. Addition and scalar multiplication of polynomials are defined as usual, i.e., =(a+d)x3 + (b + b,)x2 + (c + c')x + (d + d'), k(ax3 + bx2 + cx + d) = kar3 +kbx2 +kx + kd. Our goal is to prove that P3, with these operations, is a vector space. In this problem, you are asked to prove axiom (SM1). Put 9 of the following sentence fragments in order to form a logically correct proof of (SM1). There is only one correct answer, so be sure not to skip any steps