For this case what you can do is the following rule of three:
m ---> 100%
x ----> 115%
Clearing the value of x we have:
x = (115/100) * (m)
x = 1.15 * (m)
Answer:
a simplified expression to represent the number of members this year is:
x = 1.15 * (m)
First, find what one lightbulb costs.
9.85 / 5 = 1.97
Then multiply the product by 7.
1.97 * 7 = 13.79
Seven light bulbs will cost $13.79
If you round 13.245 seconds to the nearest tenth, the answer is 13.2 seconds.
Hope this helped!