Question

Which of the following statements best describes the graph of 4x - y = 1?

It is a straight line joining the points (0, -1), (1, 3), and (-1,-5).
It is a straight line joining the points (4, -3), (-1,2), and (-4,5).
It is a curve joining the points (4, -1), (2, 3), and (4,1).
It is a curve joining the points (0, -1), (-1, -3), and (1,5).

Answer 1

It is a straight line joining the points (0, -1), (1, 3), and (-1,-5)

Explanation:

The linear equation is an equation of a line, not a curve, so the last two choices can be eliminated.

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It is sufficient to try one point from each of the groups of points to see which group has points on the line.

First point, first choice: 4·0-(-1) = 1 . . . a point on the line

First point, second choice: 4·4 -(-3) = 19 ≠ 1 . . . not on the line

The first answer choice is appropriate.