Answer:
30
Step-by-step explanation:
To find the determinant of a 3x3 matrix, you can use this method. (See picture.)
Start with the first number in the top row, and block off the row and column. A 2x2 matrix will be left. Find the determinant of this 2x2 matrix, and multiply it by the number in the top row.
Repeat for the other two numbers in the top row. Add the first result, subtract the second, and add the third.
det A = -2 [(3)(-5) − (a)(0)] − 2 [(0)(-5) − (a)(0)] + b [(0)(0) − (3)(0)]
det A = -2 (3)(-5) − 0 + 0
det A = 30
Answer:
The flower garden width would be 6 ft
Step-by-step explanation:
A = 12 ft^2 = x(x + 4) becomes:
x^2 + 4x - 12 = 0, or (by completing the square) x^2 + 4x + 4 - 4 - 12 = 0
Thus, we have (x + 2)^2 - 16 = 0, or (x + 2)^2 = 16
Taking the square root of both sides yields x + 2 = ±4.
In this context only a positive x value makes sense: x = 2 + 4 => x = 6.
The flower garden width would be 6 ft. The other dimension would be 6 - 4, or 2, ft.
Answer:
we need more information then that....
Step-by-step explanation:
Answer with explanation:
Presume that, initial water level to be, 0 mm, at a time t=0.
And water level is rising at the rate of 
.
After 6.2 years level of water will be =1.8 × 6.2
=11.16 mm
→Averge, that is increase in water level after 6.2 years is given by
→→Rate of Depreciating of water level is given by = Negative of Increase of water level=
