First when doing an inequality, if you find it easier to think of the ≤ signs as equal signs it can make it look easier.
14 = 2t + 18 = 20
Because we need to isolate the t, we need to subtract 18 from either side:
14 - 18 ≤ 2t + 18 - 18 < 20 - 18
Which then simplifies to:
-4 ≤ 2t < 2
Now, to get the t without two lots of it, we simply divide all sides by two:
-2 ≤ t < 1
So this means that t is smaller than one and bigger than or equal to -2, and the graph that shows that is C, because it includes -2 but is less than 1.
