6,174,798,604
6.174798604 x 1,000,000,000
6.174798604 x 10^9
approx. = 6.175 x 10^9
You have to add/subtract all the common variables the answer is 3x+7y
I believe by the first equation they are referring two a representation of the total amount of money made up by the two types of coins. I found this to be 0.05x + 0.10y = 3.50
In my work I solved for the amount of each coin- I assume this is what the final step of your problem entails. If you need any help understanding/ I misinterpreted something please feel free to comment and ask :)
#5c coins or x= 36
#10c coins or y= 17
The answer is f the question I’d 800times
You need to complete it between 6 and 7 miniutes, no more than 7 and no less than 6