Please help and show work if you can I only need 10, 11 and 12

Step-by-step explanation:

10). AD = BC [If ABCD is a parallelogram]

     3x + 1 = 6x - 4

     6x - 3x = 1 + 4

     3x = 5

     x =

11). If ABCD is a parallelogram,

     AB = CD

     5x - 8 = 2x + 7

     5x - 2x = 7 + 8

     3x = 15

     x = 5

12). If ABCD is a parallelogram,

     AB = CD

     AB║CD and BD is a transversal intersecting these parallel lines.

     ∠ABD ≅ ∠BDC [Alternate interior angles]

     4x - 1 = x + 38

     4x - x = 38 + 1

     3x = 39

     x = 13

12/11c

or

12

c

11

answer: i believe its b. if you sound out the sentences that sounds wrong.