Answer:
y = 8 Â
x = 12 Â Â Â Â
Step-by-step explanation:
Corresponding sides are in proportion when the polygons are similar.
(1)    7/3.5 = 3y/x           (2)   7/3.5 = (x + 4)/y
      2 = 3y/x                   2 = (x + 4)/y
     2x = 3y                    2y = x + 4
     2x - 3y = 0                 -x + 2y = 4  Multiply by 2 and add to (1)
     -2x + 4y = 8
          y = 8                -x + 2(8) = 4
                              -x + 16 = 4
                                 -x = -12
                                  x = 12
There you go. Â Hope you can follow. Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â