In three dimensions, the cross product of two vectors is defined as shown below

Then, solving the determinant

In our case,

Where we used the formula for AxB to calculate ixj.
Finally,

Thus, (i+j)x(ixj)=i-j
The geometric sequence is starting with 2 and multiplying by 3 every time. We can get the rule of this sequence by...
If 2 is a_0, 6 is a_1, 18 is a_2, etc.
a_n=2*3^n
For the 14th term, which is a_13, the value is 2*3^13.
Using a calculator because I'm too lazy to calculate 3^13 sorry, we can get.
3188646
To find your answer you would divide 21 by 3 which would be 7, once you've got 7 you would multiply it by 9 which would give you the amount of old houses that there is which would be 63.
The answer is A hope this helps
<span>2x squared - 5
= 2(x)^2 - 5
= 2(4)^2 - 5
= 2(16) - 5
= 32 - 5
= 27</span>