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.
75/135 and 18/135
just times 9 and 15, 9 and 2, and then 15 and 5
Answer:
4x-8
Step-by-step explanation:
y=-x2+6x-8
y=4x-8
DB is a median (given). It goes from vertex point D to midpoint B.
The point B is the midpoint of segment AC. So B cuts AC into two equal halves: AB and AC
Meaning AB = AC
AC = AB+BC ... segment addition postulate
AC = AB+AB ... substitution; replace BC with AB (valid because AB = AC)
AC = 2*AB
2*AB = AC
2*AB = 50 ... substitution; replace AC with 50
2*AB/2 = 50/2 ... divide both sides by 2
AB = 25 which is the answer
The answer to the missing value is X = 3