When is the sum of two integers a negative number

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

An elevator travels 310 feet in 10 seconds. at that speed, how far can't his elevator travel in 12 seconds?

The slope of the line passing through the points (2, 7) and (-4, 8) is