Answer:
£631.07
Step-by-step explanation:
Increasing a value by 3% is the same as taking 103% of it - you have the original price (100%) plus an additional 3% of it. Let's call the original price here p. We're told that after a 3% increase, the price goes up to £650. Put another way: 103% of p is £650. In equation form:

To solve for p, we can simply divide both sides of our equation by 1.03 to get

So our orignal amount, to the nearest penny, was £631.07
Answer: 6.9
Step-by-step explanation:
If you notice the terms, they're
7, -21, 63, -189 and so forth.
7*-3 = -21 and -21 * -3 is 63 and so forth, meaning the "common ratio" is -3.
now, for a common ratio say "r", which is a fraction, namely less than ±1 and more than 0, or |r| < 1 , you do have a convergent sequence.
however this one notice, |-3| is 3, and that's greater than 1 clearly, therefore is divergent, meaning the summation has no finite value.
3 > 1
(4^0 is one)
3 is greater than 4^0
Pretty simple.