Answer:
Step-by-step explanation:
Incorrect. She forgot to change the sign while distributing.
5x - 3(4-x) = 5x - 12 + 3x = 8x - 12
Answer:
see explanation
Step-by-step explanation:
The inverse of a matrix A = ![\left[\begin{array}{ccc}a&b\\c&d\\\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Da%26b%5C%5Cc%26d%5C%5C%5Cend%7Barray%7D%5Cright%5D)
is
= 
![\left[\begin{array}{ccc}d&-b\\-c&a\\\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Dd%26-b%5C%5C-c%26a%5C%5C%5Cend%7Barray%7D%5Cright%5D)
If ad - bc = 0 then the matrix has no inverse
A = ![\left[\begin{array}{ccc}11&-5\\3&-1\\\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D11%26-5%5C%5C3%26-1%5C%5C%5Cend%7Barray%7D%5Cright%5D)
ad - bc = (11 × - 1) - (- 5 × 3) = - 11 - (- 15) = - 11 + 15 = 4 , then
= 
![\left[\begin{array}{ccc}-1&3\\-5&11\\\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-1%263%5C%5C-5%2611%5C%5C%5Cend%7Barray%7D%5Cright%5D)
= ![\left[\begin{array}{ccc}-0.25&0.75\\-1.25&2.75\\\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-0.25%260.75%5C%5C-1.25%262.75%5C%5C%5Cend%7Barray%7D%5Cright%5D)
2 | 3x - 5 | - 8 = 8
=> 2 | 3x - 5 | = 8 + 8
=> 2 | 3x - 5 | = 16
=> | 3x - 5 | = 16 / 2
=> | 3x - 5 | = 8
=> 3x - 5 = 8 or 3x - 5 = - 8
=> 3x = 13 or 3x = - 3
=> x = 13 / 3 or x = - 1
=> x = 4 and 1/3 or x = - 1
So, the answer is the second option x = - 1 or x = 4 1/3
The graph of such solutions are just the point in the real line.
For x = 4 1/3, divide the segment from 4 to 5 in three equal parts (add two divisions between 4 and 5) and mark your point in the first division after 4.
Answer:
x ≈ 121.2 ft
Step-by-step explanation:
Using the tangent ratio in the right triangle
tan60° = 
= 
( multiply both sides by 70 )
70 × tan60° = x , then
x ≈ 121.2 ft ( to 1 dec. place )
