The sum of the given polynomial is
[tex]9{x}^{2} - 12{y}^{2} - 11x = 0[/tex]
What is polynomial sum?
The given polynomial expression is:
[tex](8 {x}^{2} - 9 {y}^{2} - 4x) + ( {x}^{2} - 3{y}^{2} - 7x)[/tex]
Remove the brackets
[tex]8 {x}^{2} - 9 {y}^{2} - 4x+ {x}^{2} - 3{y}^{2} - 7x[/tex]
Collect like terms
[tex]8 {x}^{2} + {x}^{2} - 9 {y}^{2} - 3{y}^{2} - 7x - 4x = 0[/tex]
Simplify the expression above
[tex]9{x}^{2} - 12{y}^{2} - 11x = 0[/tex]
Therefore the sum of the given polynomial is:
[tex]9{x}^{2} - 12{y}^{2} - 11x = 0[/tex]
Learn more on polynomials here: https://brainly.com/question/2833285
