Jared Diamond argues the spread of agriculture and wealth is tied to physical geography. To support his argument, he stated agriculture diffused along what pattern? (A) In a north/south direction
(B) Along lines of latitude
(C) Along lines of longitude
(D) Alone lines of time zones
(E) Based on intelligence and culture of the society

if triangle abc is congruent to triangle def, their interior angles are congruent, because congruent parts of congruent triangles are congruent (cpctc).

that means ∠d is congruent to ∠a; ∠d is equal to 8x - 2.

interior angles of all triangles add to equal 180 degrees, so you can set the sum of these interior angle values equal to 180 and solve for x.

180 = (8x - 2) + 22 + 72

180 = 8x - 2 + 22 + 72

180 = 8x + 92

88 = 8x

11 = x

x = 11