One way is to subsitute the point (-1,5) for every function and see which one gives a true statement
5=10(2)^(-1) is true
5=10(0.5)^-1 is false
5=5(-1) is false
5=5(2)^-1 is false
answer is y=10(2)ˣ
Given:
The selling price of a ratio set = 72.00
Profit percent = 8%
To find:
The cost price for the radio set.
Solution:
Let x be the cost price for the radio set.
Radio set is sold at 8% profit.
The selling price of a ratio set is 72.00.
Therefore, the cost price for the radio set is 67.