Question

4) Calculando os determinantes abaixo:

A) | 2 3 –5 |

| 1 2 0 |

| 4 –1 6 |

B) | 3 1 2 |
| 4 -3 1 |
| -1 6 5 |

C) | 1 9 6 |
| -8 4 7 |
| 0 0 1 |

quem poder ajudar é pra hoje!!!!:-)

Answer 1

$\Large\boxed{\begin{array}{l}\tt a)~\begin{vmatrix}\sf2&\sf3&\sf-5\\\sf1&\sf2&\sf0\\\sf4&\sf-1&\sf6\end{vmatrix}\\\sf=2\cdot(12-0)-3\cdot(6-0)-5\cdot(-1-8)\\\sf=24-18+45\\\sf=51\end{array}}$

$\Large\boxed{\begin{array}{l}\tt b)~\begin{vmatrix}\sf3&\sf1&\sf2\\\sf4&\sf-3&\sf1\\\sf-1&\sf6&\sf5\end{vmatrix}\\\sf=3\cdot(-15-6)-1\cdot(20+1)+2\cdot(24-3)\\\sf=-63-21+42\\\sf=-42\end{array}}$

$\Large\boxed{\begin{array}{l}\tt c)~\sf\begin{vmatrix}\sf1&\sf9&\sf6\\\sf-8&\sf4&\sf7\\\sf0&\sf0&\sf1\end{vmatrix}\\\sf=1\cdot(4)-9\cdot(-8)+6\cdot(0)\\\sf=4+72\\\sf=76\end{array}}$