Answer:
33.33
Step-by-step explanation:
Answer:
see explanation
Step-by-step explanation:
Given matrix A =
, then
detA = ad - bc
Given
A = ![\left[\begin{array}{ccc}5&1\\a+1&a\\\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D5%261%5C%5Ca%2B1%26a%5C%5C%5Cend%7Barray%7D%5Cright%5D)
detA = 5a - (a + 1) = 5a - a - 1 = 4a - 1
and
4a - 1 = 7 ( add 1 to both sides )
4a = 8 ( divide both sides by 4 )
a = 2
Thus
A = ![\left[\begin{array}{ccc}5&1\\3&2\\\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D5%261%5C%5C3%262%5C%5C%5Cend%7Barray%7D%5Cright%5D)
A² - 7A + 7I
A² =
![\left[\begin{array}{ccc}5&1\\3&2\\\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D5%261%5C%5C3%262%5C%5C%5Cend%7Barray%7D%5Cright%5D)
=
= ![\left[\begin{array}{ccc}28&7\\21&7\\\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D28%267%5C%5C21%267%5C%5C%5Cend%7Barray%7D%5Cright%5D)
7A= 7
=
= ![\left[\begin{array}{ccc}35&7\\21&14\\\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D35%267%5C%5C21%2614%5C%5C%5Cend%7Barray%7D%5Cright%5D)
7I = 7
= ![\left[\begin{array}{ccc}7&0\\0&7\\\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D7%260%5C%5C0%267%5C%5C%5Cend%7Barray%7D%5Cright%5D)
Thus
-
+ ![\left[\begin{array}{ccc}7&0\\0&7\\\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D7%260%5C%5C0%267%5C%5C%5Cend%7Barray%7D%5Cright%5D)
=
= ![\left[\begin{array}{ccc}0&0\\0&0\\\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D0%260%5C%5C0%260%5C%5C%5Cend%7Barray%7D%5Cright%5D)
Hence
7A² - 7A + 7I = 0
Five plus five plus five plus five plus five
Answer:
angle four equals angle 7 because they are alternate angles in a way.
Step-by-step explanation:
First if you go diagonally up from angle 4, you get angle 5. Then you go diagonally down. That angle isn't marked so I'll call it Z. But you could do it a faster way. You see, you could replace angle 4 with angle Z and vice versa. Then angle Z is the alternate angle of angle 7. One rule you should remember:
Alternate angles are equal.
Does this help? If it doesn't make sense let me know. (When I was learning this, it didn't make sense either)
Answer:
4^2 + (-7)^2
Step-by-step explanation:
The square of the distance is given by the distance formula as ...
d^2 = (x2 -x1)^2 + (y2 -y1)^2 = (3 -(-1))^2 + (-5-2)^2
= 4^2 +(-7)^2 . . . . . matches the second choice (sort of)
_____
<em>Comment on notation</em>
Clearly, you understand the use of the caret (^) to signify exponentiation. The number 42 is very different from the value of 4^2 = 16. A caret is required.