Answer:
117°
Step-by-step explanation: We know that the angles of a triangle have to equal 180°. We already know one angle (75°) and we can find the others. Vertical angles are congruents so the angle opposite 42° is also 42° So add 42 and 75 and you get 117. Keep in mind that all the angles have to equal 180 so 180-117 will get you the last angle measure. 180-117= 63. BUT that's not the answer because that is not x and it asks for x. So we know that a straight line also equals 180 that angle that we found that was 63 plus x should get us 180. To find that we do 180-63 and find that x=117° Hope this made sense!