When vinegar and baking soda react, the mixture becomes cold to the touch and a gas and a new liquid substance are formed. Which best describes what is occurring in the reaction?

The reaction is chemical and endothermic.
The reaction is chemical and exothermic.
The reaction is non-chemical and endothermic.
The reaction is non-chemical and exothermic

The reaction is chemical and endothermic

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