Which property is demonstrated? (12×7)×5=12×(7×5)

Commutative Property of Multiplication

Associative Property of Addition

Associative Property of Multiplication

Commutative Property of Addition

What’s the range cuz i can’t find it?

The figure shows triangle def and line segment bc, which is parallel to ef: triangle def has a point b on side de and point c on side df. the line bc is parallel to the line ef. part a: is triangle def similar to triangle dbc? explain using what you know about triangle similarity. part b: which line segment on triangle dbc corresponds to line segment ef? explain your answer. part c: which angle on triangle dbc corresponds to angle f? explain your answer. asap

Fast! find the length of cu. the triangles are similar. show your work.