because these triangles share two congruent sides, the third will also be congruent.
set the equations equal to each other.
4x + 8 = 7x - 4
then combine like terms
-3x = -12
then divide to isolate the x
-12/-3 = x
4 = 4
you can then plug it in to both sides to see if it is equal/correct
4(4) + 8 = 7(4) -4
16 + 8 = 28 - 4
24 = 24
