Question

Could x = - 5 be a solution to the inequality
-6 < 3x + 9 < 21?

Answer 1

Explanation:

`3x + 9 = 3( - 5) + 9 \\ = - 15 + 9 \\ = - 6`

3x+9 is equals to -6 , not more than based on the inequality, but it is lesser than 21.

However, the solution must fulfil both criteria to be a solution to the inequality. Therefore x = -5 is not a solution to the inequality.