Here's a diagram with all the angles labeled with letters so that it is easier to talk about.
9)
m∠E = 55° because it is the other base angle of an isosceles triangle.
m∠D = 180° - 55° - 55° = 70° because the sum of the interior angles in a triangle is 180°
m∠C = m∠D = 70° because they are vertical angles and vertical angles are congruent.
m∠B = m∠C = 70° because they are base angles of an isosceles triangle.
m∠A = 180° - 70° - 70° = 40°
And so...back to the main question...
m∠2 = m∠A = 40° And so...
40 = 7x - 2
Solve the above equation for x to get the final answer.
10)
m∠I = 76° because they are base angles of an isosceles triangle.
m∠H = 180° - 76° - 76° = 28° because the sum of the interior angles in a triangle is 180°
m∠G = 90° - m∠H = 90° - 28° = 62° because the sum of ∠G and ∠H is 90°
m∠F = m∠G = 62° because they are base angles of an isosceles triangle
And so....back to the main question...
m∠2 = m∠F = 62°
62 = x + 74
x = -12