Answer:
a, -b
Step-by-step explanation:
When x is a, the function becomes

as you see, a-a is 0, and as your whole function is multiplied by this, it makes it 0.

As you see -b+b is 0, and once again, this would make the whole function 0.
<span> To get an explicit formula, we need to find an expression which gives the n-th term without having to compute earlier terms in the sequence. Looking at the numbers, and from the recursive formula, we see that the sequence is built by subtracting n from the previous term. This is similar to the triangular number sequence 1,3,6,10,15,... which has the explicit formula a_n = n(n+1)/2. In our case we are subtracting n from the previous term, so we multiply by -1/2 instead of 1/2. However, we also need to add a constant term to reproduce the numbers of the sequence. We can write a_1 = -1(2)/2 + c = 8. Therefore, c = 9.
So the explict formula is:
a_n = -n(n+1)/2 + 9</span>
Substitute the number for the appropriate variables and solve
(ab)^2
(4×3)^2
(12)^2
12×12
144
Your answer is B.144
24 pencils in each box...
you would take 196 and minus it by 4 which is 192, then divide 192 by 8, which will give you 24 then 4 left over pencils