X= 9 2/7 ( the first answer is correct )
Answer:
3rd. row becomes [0 0 -6 1]
Step-by-step explanation:
The element of pivot is the 9 in the 2nd row, so the 1st and 2nd rows stays the same.
For the 3rd row we have to calculate in each column, the element of the 3rd row minus the element of the 2nd row, and put it in the 3rd row.
This way we have <em>four operations</em> as follow:




for columns 1 to 4 in that order.
With this procedure, the system becomes
[1 –2 3 1]
[0 9 2 –5]
[0 0 –6 1]
To get $74 in change using only Quarters and dimes would be 210 Quarters and 215 dimes which 210 quarters adds up too $52.50 and 215 dimes would add up too $21.50 add those together and you get $74 dollars exactly
Answer:
60 degrees
Step-by-step explanation:
You can use this triangle in a Pythagorean Theory. It means that angles inside are 90 degrees, 60 degrees, and 30 degrees. It is bigger than angle E so it have to be 60 degrees.
Hope that I helped
Answer: 1. about 7 kil
2. 72.5
3. 8.75
Step-by-step explanation: