now in subtraction of polynomials how would you write the problem -7x^2+(3x)+(9) from 5x^2+6x+4.I know you change the signs, but it is not working so i am asking how would you write this problem

5x

^{2}+ 6x + 4-(-7x

^{2 }+ 3x + 9)Change the signs and add:

5x

+ 7x

^{2}+ 6x + 4+ 7x

^{2}- 3x - 9-------------------

**12x**

^{2}+ 3x - 5You can also do it as follows:

(5x

^{2}+6x+4) - (-7x^{2}+3x+9)Change signs and add:

5x

^{2 }+ 6x + 4 + 7x^{2}- 3x - 9Combine like-terms:

(5x

^{2}+7x^{2}) + (6x-3x) + (4-9)**12x**

^{2}+ 3x - 5