Answer:
[tex] \boxed{ \bold{ \boxed{ \sf{ {x}^{4} + 3 {x}^{3} - 9 {x}^{2} - 12x + 20}}}}[/tex]
Step-by-step explanation:
[tex] \sf{( {x}^{2} - 4)( {x}^{2} + 3x - 5)}[/tex]
Use distributive property
[tex] \dashrightarrow{ \sf{ {x}^{2} ( {x}^{2} + 3x - 5) - 4( {x}^{2} + 3x - 5)}}[/tex]
[tex] \dashrightarrow{ \sf{ {x}^{4} + 3 {x}^{3} - 5 {x}^{2} - 4 {x}^{2} - 12x + 20}}[/tex]
Collect like terms
[tex] \dashrightarrow{ \sf{ {x}^{4} +3 {x}^{3} - 9 {x}^{2} - 12x + 20}}[/tex]
Hope I helped!
Best regards! :D
