-3 x -26 = 78
meaning the answer is D.
The reason the answer is D, is because two negatives when multiplied or divided become positive. Only when multiplied or divided does this occur.
your question answer is 12360
21 divide by 4 is 5.25. She travels 5.25 miles per hour. 42 divide by 5.25 is 8. It would take 8 hours for Shelly to bike 42 miles.