Answer:
10x - 15
Explanation:
let Emily's be x hrs
Abbey = 3x-5 hrs
Nathan = 2 * Abbey's time= 2(3x-5)
= 6x-10 hrs
Expression= x + 3x-5 + 6x-10 = 10x - 15 hrs
Therefore, 10x - 15 is the EXPRESSION THAT DENOTES THE TOTAL NUMBER OF HOURS SPENT FOR DOING HOMEWORK COLLECTIVELY.