Peter has saved $10. he doubles the amount he saves each week. does this represent a exponential function? if so, write down the function.

Step-by-step explanation:

This is an exponential function.  Peter is not simply adding $10 a week to his savings, he's doubling each value each week.  The first case of adding $10 a week is linear.  

The standard form of an exponential equation is

where a is the initial amount and b is the growth or decay factor.  We know a = 10 because we are told he started with $10.  After the first week he would have $20 then because $10 doubled is $20.  That coordinate is (1, 20).  We will use that in place of x and y and solve for b:

b to the first is just b, so what we have essentially is 10b = 20, so b = 2.  The equation then is:

7

step-by-step explanation:

the answer would be 7

4 and 5)16.97 or 12√2

6)15.59 or 9√3

7)y = 15.59 or 9√3     x =27

8)17.80