Question
Mathematics Question on Determinants
If x is a positive integer, then x!\[0.3em](x+1)!\[0.3em](x+2)!(x+1)!(x+2)!(x+3)!(x+2)!(x+3)!(x+4)! is equal to
A
2x!(x+1)!
B
2x!(x+1)!(x+2)!
C
2x!(x+3)!
D
2(x+1)!(x+2)!(x+3)!
Answer
2x!(x+1)!(x+2)!
Explanation
Solution
x!\[0.3em](x+1)!\[0.3em](x+2)!(x+1)!(x+2)!(x+3)!(x+2)!(x+3)!(x+4)! = x!(x+1)!(x+2)! 1 x+1 (x+2)(x+1)1x+2(x+2)(x+3)1(x+3)(x+3)(x+4) = 2x!(x+1)!(x+2)!