Answer: x=8
Step-by-step explanation: since we know 2 sides of both quadrilaterals and they are similar,
just put 32/40 = 24/3x+6 ,
cross multiply ( 32 x 3x+6 and 40 x 24),
they become 96x +192 = 960.
move 192 to the other side and divide both sides by 96