Answer:
Step-by-step explanation:
![\left[\begin{array}{ccc}7&31\\142&19\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D7%2631%5C%5C142%2619%5Cend%7Barray%7D%5Cright%5D)
= 7(19) - 142(31) = <em>- 4269</em>
![\left[\begin{array}{ccc}7&11&21\\55&-8&2\\-16&-1&-9\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D7%2611%2621%5C%5C55%26-8%262%5C%5C-16%26-1%26-9%5Cend%7Barray%7D%5Cright%5D)
= 7(- 8)(- 9) + 11(2)(- 16) + 21(55)(- 1) - 21(- 8)(- 16) - 7(2)(- 1) - 11(55)(- 9) = <em>1768</em>
![\left[\begin{array}{ccc}9.07&6.02&2.01\\-30.7&2.5&3.5\\3.55&-1.1&2.35\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D9.07%266.02%262.01%5C%5C-30.7%262.5%263.5%5C%5C3.55%26-1.1%262.35%5Cend%7Barray%7D%5Cright%5D)
= 9.07(2.5)(2.35) + 6.02(3.5)(3.55) + 2.01(- 30.7)(- 1.1) - 2.01(2.5)(3.55) - 9.07(3.5)(- 1.1) - 6.02(- 30.7)(2.35) = <em>647.3561</em>
X(7x+3)=0
x=0
or
7x=-3
x=-3/7
so,
(0,0) or (-3/7,0)
Add 6 to left middle and right
then, divide them all by 3
