Answer:
Letter C.
Explanation:
Let’s start by subtracting \blue{18}18start color #6495ed, 18, end color #6495ed from both sides of the inequality:
\qquad \begin{aligned} 5a + 18 &< -27\\ 5a + 18 \blue{-18} &< -27\blue{-18}\\ 5a &< -45\\ \end{aligned}
5a+18
5a+18−18
5a
<−27
<−27−18
<−45
Hint #22 / 4
To isolate aaa, we need to divide both sides by \green{5}5start color #28ae7b, 5, end color #28ae7b:
\qquad\begin{aligned} 5a &< -45\\ \\ \dfrac{5a}{\green{5}} &< \dfrac{-45}{\green{5}}\\ \\ a &< \purple{-9}\\ \end{aligned}
5a
5
5a
a
<−45
<
5
−45
<−9
Hint #33 / 4
To graph the inequality a < \purple{-9}a<−9a, is less than, start color #9d38bd, minus, 9, end color #9d38bd, we first draw a circle at \purple{-9}−9start color #9d38bd, minus, 9, end color #9d38bd. This circle divides the number line into two sections: one that contains solutions to the inequality and one that does not.
Since the solution uses a less than sign, the solution does not include the point where a= \purple{-9}a=−9a, equals, start color #9d38bd, minus, 9, end color #9d38bd. So the circle at \purple{-9}−9start color #9d38bd, minus, 9, end color #9d38bd is not filled in.
Because the solution to the inequality says that a < \purple{-9}a<−9a, is less than, start color #9d38bd, minus, 9, end color #9d38bd, this means that solutions are numbers to the left of \purple{-9}−9start color #9d38bd, minus, 9, end color #9d38bd.
Hint #44 / 4
The graph that represents the solution of the inequality a < \purple{-9}a<−9a, is less than, start color #9d38bd, minus, 9, end color #9d38bd is shown in