That would mean we're doubling the number of peanuts to get raisins. So, we would have 2x+y for the total amount.
From the given recurrence, it follows that

and so on down to the first term,

(Notice how the exponent on the 2 and the subscript of <em>a</em> in the first term add up to <em>n</em> + 1.)
Denote the remaining sum by <em>S</em> ; then

Multiply both sides by 2 :

Subtract 2<em>S</em> from <em>S</em> to get

So, we end up with

Answer:
Can you please attach a picture of the question so I can help?
Step-by-step explanation:
The answer is 1/20 .............
1.0g/cm3 means that the mass of one cm3 is 1.0g
The easiest method to use is the rule of three, and let x be the mass of 10.0 cm3 of water
1g -- > 1.0 cm3
x --> 10.0 cm3
x= (10*1)/1
x=10.0 g
So the mass of 10.0 cm3 of water is 10.0g
Hope this Helps! :)