It's a lengthy procedure to detail it.
Review your course and Apply the here below determinant value and you will find the determinant of this matrix = -35
A₁₁ A₁₂ A₁₃
A₂₁ A₂₂ A₂₃
A₃₁ A₃₂ A₃₃
DETERMINANT (A) =
A₁₁(A₂₂A₃₃ - A₃₂A₂₃) - A₁₂(A₂₁A₃₃ - A₂₃A₃₁) + A₁₃(A₂₁A₃₂ - A₂₂A₃₁
