what are the first four terms of the sequence represented by the expression n(n-1)-5?
A: -7,-5,-3,1
B: -5,-10,-15,-25
C: 0, 2, 6, 12
D: -5,-3,1,7
To find the first four terms of the sequence, we simply need to plug in the first four positive integers into the expression and simplify:
For n = 1: 1(1-1)-5 = -5
For n = 2: 2(2-1)-5 = -3
For n = 3: 3(3-1)-5 = 1
For n = 4: 4(4-1)-5 = 7
Therefore, the first four terms of the sequence are -5, -3, 1, and 7. The answer is option D: -5,-3,1,7.
To find the first four terms of the sequence represented by the expression n(n-1)-5, we substitute different values of n into the expression:
For n = 1:
1(1-1)-5 = -5
For n = 2:
2(2-1)-5 = -3
For n = 3:
3(3-1)-5 = 1
For n = 4:
4(4-1)-5 = 7
The first four terms of the sequence represented by the expression n(n-1)-5 are -5, -3, 1, and 7.
Therefore, the correct answer is option D: -5, -3, 1, 7.