Answer:
[tex]- 5 {x}^{3} - {x}^{2} - 11x + 7 \\ [/tex]
Step-by-step explanation:
Before solving that we have to know that,
[tex]( + ) \times ( + ) = ( + ) \\ ( - ) \times (- ) = ( + ) \\ ( + ) \times ( - ) = (- )[/tex]
Let's solve now.
[tex]7 {x}^{3} - 11x - 1 - (12 {x}^{3} + {x}^{2} - 8) \\ 7 {x}^{3} - 11x - 1 - 12 {x}^{3} - {x}^{2} + 8 \\ 7 {x}^{3} - 12 {x}^{3} - {x}^{2} - 11x - 1 + 8 \\ = - 5 {x}^{3} - {x}^{2} - 11x + 7[/tex]
Hope this helps you.
Let me know if you have any other questions :-):-)
