Answer:
483 840 ways
Step-by-step explanation:
Let you and your friend be A and B.
With three people always between you two,, we have
Case 1: AxxxBxxxxx
Case 2: xAxxxBxxxx
Case 3: xxAxxxBxxx
Case 4: xxxAxxxBxx
Case 5: xxxxAxxxBx
Case 6: xxxxxAxxxB
So there is 6 ways of arranging you two through the line and for each of the six cases,
If you two remained in your positions, the rest can be arranged in 8! ways
Also for each case, you two can interchange your positions in 2! ways
Therefore,
The photographer can rearranged the line keep three people between you an your friend in
8! * 2! * 6 = 483 840 ways
Answer:
-7
Step-by-step explanation:
Associate property
It’s right
Answer:
(x+1)(x-1)(x+3)(x-3)
Step-by-step explanation:
x4-10x^2+9
Group expression so that the coefficients of the x^2 terms add up to +9.
= x^4 -9x^2 - x^2+9
match coefficients in both groups
= x^4 -9x^2 - (x^2-9)
factor each group
= x^2 (x^2-9) - 1(x^2-9)
now factor out the common factor (x^2-9)
= (x^2-1)(x^2-9)
Finally, factor each quadratic factor
= (x+1)(x-1)(x+3)(x-3)
