Question

The boundary line for the inequality
x
+
4
y
<
−
20
is given.



A dashed line passes through the points (-4, -4), (0, -5) and (4, -6).



Is each ordered pair a part of the solution set of the linear inequality? Select Yes or No for each ordered pair in the table.



Ordered Pair

Row Headers
Yes

No

(
0
,
−
5
)

(0,-5) and Yes (0,-5) and No
(
7
,
−
4
)

(7,-4) and Yes (7,-4) and No
(
−
6
,
−
7
)

(-6,-7) and Yes (-6,-7) and No
(
−
4
,
1
)

(-4, 1) and Yes (-4, 1) and No
(
4
,
−
8
)

(4,-8) and Yes (4,-8) and No

Answer 1

We test x + 4y < −20 for each point.

- (0, −5): 0 + 4(−5) = −20 → equals boundary, not < → No
- (7, −4): 7 + 4(−4) = −9, and −9 < −20 is false → No
- (−6, −7): −6 + 4(−7) = −34, and −34 < −20 is true → Yes
- (−4, 1): −4 + 4(1) = 0, and 0 < −20 is false → No
- (4, −8): 4 + 4(−8) = −28, and −28 < −20 is true → Yes