Now, I'm going to bring back the inequality or < symbol. I only removed it when simplifying and isolating [tex]d[/tex], but if this confuses you, just do your math and keep the inequality there.
[tex]d[/tex] < [tex]6[/tex]
On a number line, this would include every number less than [tex]6[/tex], due to the < (less than) symbol. This disqualifies answers b and d because they are showing every number greater than [tex]6[/tex]. But, how do we decide between answers a and c?
If a line has point at its beginning, [tex]6[/tex], then that means that every number less than or equal to [ ≤ ] 6 is being shown, but our equation just says less than [ < ] 6, so answer a is our correct answer.
