Δabc is isosceles. if m∠a = 100°, m∠b = (12x + 4)°, and m∠c = (14x - 2)°, find x.

I am trying to imagine this and it sounds like the two base angles, which are equal, are (12x+4) and (14x-2).  And since this is a triangle the sum of these two angles must be 180-100=80°

12x+4+14x-2=80

26x+2=80

26x=78

x=3

Since we know that they are equal we could also just have said:

12x+4=14x-2

-2x=-6

x=3

:P