the 2 equations given are vertical angles which mean they would equal the same.
Set the two equations to equal each other to solve for x:
6(x-2) = 3x+30
Simplify the left side:
6x-12 = 3x+30
Add 12 to eac side:
6x = 3x+42
Subtract 3x from each side"
3x = 42
Divide both sides by 3:
X = 42/3
X = 14
Now you know X, replace x with 14 in the equation for DHG:
DHG = 6(x-2)
6(14-2)
Simplify:
6(12)
Multiply:
72
Angle DHG is 72 degrees.