18. Which point(s) are solutions to the inequality [tex]-x-2y\ \textgreater \ 3[/tex]? Select all that apply.

A. [tex](-1,-2)[/tex]
B. [tex](1,-2)[/tex]
C. [tex](-2,-1)[/tex]
D. [tex](2,-4)[/tex]



Answer :

To determine which points are solutions to the inequality [tex]\( -x - 2y > 3 \)[/tex], we need to evaluate each point individually and see if the inequality holds true. Let's go through each of the given points one by one.

### Point (A) [tex]\((-1, -2)\)[/tex]

Substitute [tex]\( x = -1 \)[/tex] and [tex]\( y = -2 \)[/tex] into the inequality:
[tex]\[ -x - 2y > 3 \][/tex]
[tex]\[ -(-1) - 2(-2) > 3 \][/tex]
[tex]\[ 1 + 4 > 3 \][/tex]
[tex]\[ 5 > 3 \][/tex]

This is true. Hence, the point [tex]\( (-1, -2) \)[/tex] satisfies the inequality.

### Point (B) [tex]\((1, -2)\)[/tex]

Substitute [tex]\( x = 1 \)[/tex] and [tex]\( y = -2 \)[/tex] into the inequality:
[tex]\[ -x - 2y > 3 \][/tex]
[tex]\[ -(1) - 2(-2) > 3 \][/tex]
[tex]\[ -1 + 4 > 3 \][/tex]
[tex]\[ 3 > 3 \][/tex]

This is false since 3 is not greater than 3. Hence, the point [tex]\( (1, -2) \)[/tex] does not satisfy the inequality.

### Point (C) [tex]\((-2, -1)\)[/tex]

Substitute [tex]\( x = -2 \)[/tex] and [tex]\( y = -1 \)[/tex] into the inequality:
[tex]\[ -x - 2y > 3 \][/tex]
[tex]\[ -(-2) - 2(-1) > 3 \][/tex]
[tex]\[ 2 + 2 > 3 \][/tex]
[tex]\[ 4 > 3 \][/tex]

This is true. Hence, the point [tex]\( (-2, -1) \)[/tex] satisfies the inequality.

### Point (D) [tex]\((2, -4)\)[/tex]

Substitute [tex]\( x = 2 \)[/tex] and [tex]\( y = -4 \)[/tex] into the inequality:
[tex]\[ -x - 2y > 3 \][/tex]
[tex]\[ -(2) - 2(-4) > 3 \][/tex]
[tex]\[ -2 + 8 > 3 \][/tex]
[tex]\[ 6 > 3 \][/tex]

This is true. Hence, the point [tex]\( (2, -4) \)[/tex] satisfies the inequality.

### Conclusion

The points that satisfy the inequality [tex]\( -x - 2y > 3 \)[/tex] are:

- [tex]\((-1, -2)\)[/tex]
- [tex]\((-2, -1)\)[/tex]
- [tex]\((2, -4)\)[/tex]

Thus, the correct points are:

(A) [tex]\((-1, -2)\)[/tex]

(C) [tex]\((-2, -1)\)[/tex]

(D) [tex]\((2, -4)\)[/tex]