15x15= 225
15x + 105= 225
15x= 225-105
15x= 120
X=8
X+ (x+1) + (x+2) + (x+3)…etc all the way up too +(x+14)=225
The first five numbers of the set: 8, 9, 10, 11, 12
Answer:
364.5
Step-by-step explanation:
you would need a calculator for it, unless you can do exponential math at such a degree... if you're using a PC there's a good graphing calculator at Desmos.com, it can show you how a graph looks, which shows that when n is 7, the answer is 364.5. also it wouldn't be 1093.5 because the exponent is n-1 which means that while n could be 7, you need to take away 1 before using it as an exponent.
Answer:

Step-by-step explanation:

Subtract 57 from both sides:

Divide both sides by 4:
