Part a:
The complete question is shown in the attached image.
Now, to get the solution of the inequality, we will have to isolate the "t" on one side on the inequality as follows:
3t + 1 < t + 12
3t + 1 - t < t + 12 - t
2t + 1 < 12
2t + 1 - 1 < 12 - 1
2t < 11
2t/2 < 11/2
t < 5.5
Part (b):
I found the correct syntax of the question in other resources.
The question statement is:
2t² = 72. Find the value of t
Now, we will get the value of t as follows:
2t² = 72
t² = 72/2
t² = 36
t = ±√36
either t = +√36 = 6
or t = -√36 = -6
Solution set is {-6,6}
Hope this helps :)