Multiple Choice Question (MCQ)
Which point (x, y) is a solution to the given inequality y < −4x + 4 in
the xy-plane?
-
×
(2, −1)
-
×
(2, 1)
-
×
(0, 5)
-
✓
(−4, 0)
Answer
-
(2, −1)
f(x) = −4x + 4
f(2) = -4\cdot 2 +1 = -7
-1 > -7
Therefore
A is incorrect
-
(2, 1)
f(x) = −4x + 4
f(2) = -4\cdot 2 +1 = -7
1 >-7
Therefore
B is incorrect
-
(0, 5)
f(x) = −4x + 4
f(2) = -4\times 0 +1 = 1
5 > 1
Therefore
C is incorrect
-
(−4, 0)
f(x) = −4x + 4
f(-4) = -4\times (-4) +1 = 17
0 < 17
Therefore
D is correct