The answer is 45 because 2.50 times 18=45
The first 5 outputs are:

As you can see, the outputs keep doubling each time we increment x by 1.
This can be written formally, observing that if you know the value of
, the next value will be

So, again, we've shown that the next value is twice the previous one, so you have

You just have to go 7x28=[7x20]+[7x8]=196
When you add, you subtract the exponents. When you divide, you subtract the exponents.
When you have multiplication and division in one expression, you do it from left to right.
7^2 times 7^5 = 7^ (2+5) = 7^7
7^7 times 2^2 / 7^3 = 7 ^(7 - 3) times 2^2
7^4 times 2^2 times 2^6 = 7^4 times 2^(2+6) = 7^4 times 2^8
Put it in a calculator.
614656.
That is the answer, but you didn't include the "which of the following", so I guess you'll have to put each value in the calculator to find out!
If the 7^3 times 2^6 is in parenthesis, then the answer is 150.0625.
Check the picture below
notice, using the 30-60-90 rule, since that triangle is a 30-60-90 triangle, we get 11 = 2x