PLEASE HELP ME PLEASE !

Iwant to know what 3g+5h+4g-2h is my teacher is too selfish to tell us

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

Maria solved an equation as shown below. what is the solution to maria’s equation?