Well first you substitute -3 for y and then subtract 12 from both sides of the equation and it should look like -15=-3x. Then divide 3 on both sides and you should end up getting 5=x.
Answer:
x=53
y=26
H=106
G=93
Step-by-step explanation:
By the inscribed quadrilateral conjecture:

Hope this helps!
x and x+4 are the numbers
3x=2(x+4)
3x=2x+8
3x-2x=8
x=8
x+4=12
3
it’s just how far away that number is from zero