Please help me with i ii iii Step by step
2 answers:
(i) I used distributive property to get the x’s and y’s out of parentheses. I then combined like-terms to simplify until I could do no more. That is your final answer for (i) is -3x - 12y
(ii) This one is similar to the first one, just with no parentheses. I combined like terms again until not like terms were left. Your final answer for (ii) is -3k -2 -2n
(iii) I started by dividing 15 by 3 and got 5, and because the 15 had an x to it, you get 5x. I then moved onto the next term, 9. 9 divided by 3, to get 3. Your final answer for (iii) is 5x + 3
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Answer:
Yes, it is invertible
Step-by-step explanation:
We need to find in the matrix determinant is different from zero, since iif it is, that the matrix is invertible.
Let's use co-factor expansion to find the determinant of this 4x4 matrix, using the column that has more zeroes in it as the co-factor, so we reduce the number of determinant calculations for the obtained sub-matrices.We pick the first column for that since it has three zeros!
Then the determinant of this matrix becomes:
And the determinant of these 3x3 matrix is very simple because most of the cross multiplications render zero:
Therefore, the Det of the initial matrix is : 4 * 3 = 12
and then the matrix is invertible