For this case we have the following inequality:
[tex]4d- 6< 18[/tex]
We add 6 to both sides of the inequality:
[tex]4d <18 + 6\\4d <24[/tex]
We divide between 4 on both sides of the inequality:
[tex]d <\frac {24} {4}\\d <6[/tex]
Thus, the solution is given by all values of "d" less than 6.
Answer:
[tex]d<6[/tex]
See attached image