Sure, here's how you can calculate your current grade in the class taking into account the upcoming test:

Let G be your current grade in the class, and T be your expected grade on the upcoming test (30% of the total grade).

First, find the weighted average of your current grade and the upcoming test:

Weighted average = (0.8 x G) + (0.2 x T)

Note that the weight of your current grade is 0.8 since it is worth 80% of your total grade (100% - 20% for the upcoming test).

Substitute G = 75 and T = 30 into the formula:

Weighted average = (0.8 x 75) + (0.2 x 30) = 60 + 6 = 66

So your current grade taking into account the upcoming test is 66%.