Problem: In the table shown, the formula relating x and y is:
xy1327313421531
Answer Choices:
A. y=4x−1
B. y=x3−x2+x+2
C. y=x2+x+1
D. y=(x2+x+1)(x−1)
E. none of these
Solution:
(C) is shown to be the correct choice by direct check.
Note: The fact that the y-differences are 4,6,8, and 10 can be used tc eliminate (A) and (B) immediately.