20) After 8 hours, half of a 16-gram sample of a radioactive element remains. Find the constant k for this elemen -kt
hours, then use y = ne^kt to write the equation for modeling its exponential decay.

Cole says the distance between points (-5,0) and (0,-5)is 5 units. is he correct? explain why or why not.

Luigi is the first person to finish a 5k race and is standing 13 feet beyond the finish line. another runner, mario, is still running the race and has approximately 24 feet before he reaches the finish line. what is the distance between mario and luigi? explain through words, numbers or pictures how you found the answer.

Which answer choice is it? is it the first ,second,third or fourth giving 40 points for whoever answers correctly you