方程問題????

This is algebric expression only.
We can use long division to do it.
______x^2_-x_-3____
x^2+x-2 丿x^4 - 6x^2+x+7)
x^4+x^3-2x^2
______________
-x^3-4x^2+x
-x^3-x^2 +2x
______________
-3x^2-x+7
-3x^2-3x+6
________________
2x+1 <---- remainder
= (x^4-6x^2+x+7)/(x^2+x-2) = x^2-x-3+(2x+1)/(x^2+x-2)