Hello Charlesbabegirl! :)
Hope you're having a nice day!
First of all, let's say that the sum of all internal angles of a triangle is always 180°
This means that if you add up angles A, B and C you get 180 but we should find first the value of x by setting up a proportion of this type:
A + B + C = 180
48 + 6x - 28 + 2x = 180
Move all the known terms (those that don't have x) to the right with changed sign.
6x + 2x = 180 - 48 + 28
8x = 160
Divide both terms by 8
x = 20
Then plug the value of x...
m∠B = 6(20) - 28 = 120-28 = 92°
m∠C = 2(20) = 40°
Hope I helped and let me know if I was right!