we have that
2t + 1 > 9 or –18 > 5t – 3
this is a disjunction----------> the solution set is the union of the solution sets of each inequality
2t + 1 > 9--------------> 2t > (9-1)-------------> t > 4
the solution of this inequality is (4,∞)
–18 > 5t – 3----------> -18+3 > 5t--------> -15 > 5t------> -3 > t---------> t < -3
the solution of this inequality is (-∞,-3)
the solution of this system is the union of both ------> (-∞,-3) U (4,∞)
the answer Part A) is (-∞,-3) U (4,∞)
Part B)
using a graph tool
see the attached figure
