For this case we must find the solution set of the following inequalities:
[tex]x-1> 11[/tex] or [tex]3x \leq21[/tex]
We have to:
[tex]x-1> 11[/tex]
Adding 1 to both sides:
[tex]x> 11 + 1\\x> 12[/tex]
The solution is given by all values of x greater than 12.
[tex]3x \leq21[/tex]
We divide between 3 on both sides of:
[tex]x \leq \frac {21} {3}\\x \leq7[/tex]
The solution is given by all values of x less than or equal to 7.
Thus, the solution set is given by:
[tex]x> 12[/tex] or [tex]x \leq7[/tex]
Answer:
[tex]x> 12[/tex] or [tex]x \leq7[/tex]
(-∞, 7] U (12, ∞)
