The first term is 2 and the common ratio = -8/2 = -4
S7 = 2 * (-4)^7 - 1
------------- = 6554 answer
-4-1
Remark
There's a lot you don't know here. Are DE and GF parallel? Is B a right angle? You can't assume that it is. The safest way to proceed is to give x in terms of 58 and B. You might get an answer that gives you something like 32 but I don't think you can say that unless you are told somewhere that ABC is a right angle triangle with the right angle at B.
So what to do.
<BAC = 58o That's because <BAC = <IAK They vertically opposite.
<ABC + <BAC + <ACB = 180o All triangles have 180o
<ACB = 180 - 58 - <ABC Solve for an unknown angle of a triangle.
<ACB = 122 - <ABC
x = <ACB Vertically opposite angles.
x = 122 - <ABC Answer It's 32 if ABC is a right angle.