Here is an example... ( look at the attachment bellow ) :
Then there would be 9 girls and 23 boys
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
<h3>
Answer:</h3>
- A) p = 5, one solution
- B) no solutions
- C) infinite solutions
<h3>
Step-by-step explanation:</h3>
A) Add 19-5p to each side of the equation:
... 10 = 2p
... 5 = p . . . . . divide by the coefficient of p
B) Subtract 5p from both sides of the equation:
... -9 = -19 . . . . . there is <em>no value of p</em> that will make this true. (No solution.)
C) Subtract 5p from both sides of the equation:
... -9 = -9 . . . . . this is true for <em>every value of p</em>. (Infinite solutions.)
Answer:
a + 20 = 7*12 (multiplied both sides by 12)
a + 20 = 84 (calculated 7*12)
a = 84 - 20 (subtracted 20 on both sides)
a = 64 (calculated 84-20)