MTH 030 -- Elementary Algebra -- Exercise Solutions
Section:
7.5

6a)   The point (3, 1) is not a solution of the inequality x + 4y < -1.
       When the coordinates of the point are substituted into the inequality we obtain
        1 + (4)(3) < -1 which is FALSE because 13 is not less than -1.

6b)   The point (-2, 0) is a solution of the inequality x + 4y < -1.
       When the coordinates of the point are substituted into the inequality we obtain
        0 + (4)(-2) < -1 which is TRUE because -8 is less than -1.

6c)   The point (-0.5, 0.2) is not a solution of the inequality x + 4y < -1.
       When the coordinates of the point are substituted into the inequality we obtain
        -0.5 + (4)(0.2) < -1 which is FALSE because 0.3 is not less than -1.

6d)   The point (-2, 1/4) is not a solution of the inequality x + 4y < -1.
       When the coordinates of the point are substituted into the inequality we obtain
        -2 + (4)(1/4) < -1 which is FALSE because -1 is not less than -1.