Solved: Det of 4A-1 | Find Det of 4A-1 Matrix

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SUMMARY

The determinant of the matrix expression 4A-1, given that det(A) = 7, can be calculated using properties of determinants. Specifically, scaling a matrix by a scalar multiplies the determinant by that scalar raised to the power of the matrix size. Therefore, det(4A) = 4^3 * det(A) = 64 * 7 = 448. Since det(A-1) = 1/det(A), we find that det(4A-1) = det(4A) * det(A-1) = 448 * (1/7) = 64.

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[SOLVED] Determinant problem

Homework Statement


If det(A) = 7, then what is det(4 A-1)?
where A is 3*3 matrix

Homework Equations


The Attempt at a Solution



No idea about this, please give me some hint.
 
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This is just collecting properties about determinants. If you scale one of your rows (or columns) by some scalar what is the determinant of the resulting matrix? Now, realize that 4A is multiplying every row by 4. Assuming A has an inverse, what is the determinant of the inverse?
 

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