1. The problem statement, all variables and given/known data The 4x4 matrix with rows v1, v2, v3 and v4 has a determinant of -5. What is the determinant of the matrix with rows v1, v2, 7v3+6v4, 6v3+8v4? 2. Relevant equations 3. The attempt at a solution I tried doing -5x7x8=-280 but its saying its wrong. I don't understand why. I'm using the properties of determinants of matrices.