Y= (1/2)^x hope this helps :)
First expand the parentheses:-
96x + 18 - 6 + 8x + 25 = 0
104x = -18 + 6 - 25 = -37
x = -37 / 104 = -0.3558
If you think about it, an octagon is made up of 8 triangles. So you first find the area of one triangle then multiply it by 8 for the total area:
A=1/2bh
A=1/2(9.9)(12)
A=59.4
59.4 x 8= 475.2
Therefore the total area for the octagon should be 475.2 units^2
Hope this helps !