Answer:
9. 3x² +x -2y +5 = 0
10. 4x² +x -y +4 = 0
11. 9x² -6x -3y -12 = 0
Explanation:
"General form" of a polynomial equation is ...
f(x, y) = 0
where the terms are arranged in lexicographical order and decreasing degree. That is, for terms of the same degree, x-terms are listed before y-terms, and xy terms are listed before y-only terms.
The leading coefficient can be positive or negative, your choice. (Positive is generally preferred.) For linear equations, "standard form" has the coefficients mutually prime. Making that happen for a general form polynomial would be your choice.
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9.
The highest-degree term is 3x². If we keep the leading coefficient positive, we can get general form by subtracting the expression on the left side of the equal sign.
3x² +x -2y +5 = 0
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10.
Subtracting the right side gives ...
4x² +x -y +4 = 0
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11.
Subtracting the left side gives ...
9x² -6x -3y -12 = 0
or
3x² -2x -y -4 = 0 . . . . . . remove a common factor of 3