A matrix is diagonal if

In other words, you want non-zero elements only when the indices of the row and the column are the same: the first element of the first row must be non zero, the second element of the second row must be non-zero, and so on. All other elements must be zero.
Answer:
Step-by-step explanation:
<u>Sum of n terms formula:</u>
<u>Solving for n</u>
- 3480 = 1/2n(9 + 165)
- 3480 = 87n
- n = 3480/87
- n = 40
True.
The y-axis of the f(x) must equal to the x-axis of g(x)
The x-axis of the f(x) must equal to the y-axis of g(x)
Step-by-step explanation:
Shes wrong because she did it in 3 hours which means she would have made 3 cards and not 9.