Yes they are proportionate
Answer:
Step-by-step explanation:
Step 3
4n - (7-6n)
4n -7 +6n (multiply minus to 7-6n)
10n -7 is the answer
First let's solve for the rate, "b", by setting up a ratio with the two points given:
16.875/7.5=(ar^3)/(ar)
2.25=r^2
r=1.5
Now we need to solve for the initial value a using either point given...
7.5=a(1.5)^1
7.5=1.5a
a=5
So now we have solved for both variables and have a complete equation:
y=5(1.5)^x
One way of doing it is to realize that if she buys 5 bottles, she would need exactly $6. $15.76 that she has includes 2 $6's, which means that she can buy at least 10 bottles. After these 10 bottles, she would have spent $12, therefore having $3.76 left. This is enough for 3 more bottles, costing $3.6 total. 3.76-3.6=$0.16, which is the amount she has left over, after buying a total of 13 bottles.
