7 x n =42+7
A.6
B.7
C.42
D.56
E.294

Pick the expression that matches this description: a polynomial of the 5th degree with a leading coefficient of 7 and a constant term of 6 (choice a) 7x^5+2x^2+6 (choice b) 7x^6−6x^4+5 (choice c) 6x^7−x^5+5 (choice d) 6x^5+x^4+7

Ihave trouble finding the nth term of a linear sequence

In a column proof the right column states your reasons