Answer:
(x^4 + -4 x^3 + 12 x^2 - 28)/x^2
Explanation:
Simplify the following:
x^2 + 3 x - 7 x + 12 - 28/x^2
Put each term in x^2 + 3 x - 7 x + 12 - 28/x^2 over the common denominator x^2: x^2 + 3 x - 7 x + 12 - 28/x^2 = x^4/x^2 + (3 x^3)/x^2 - (7 x^3)/x^2 + (12 x^2)/x^2 - 28/x^2:
x^4/x^2 + (3 x^3)/x^2 - (7 x^3)/x^2 + (12 x^2)/x^2 - 28/x^2
x^4/x^2 + (3 x^3)/x^2 - (7 x^3)/x^2 + (12 x^2)/x^2 - 28/x^2 = (x^4 + 3 x^3 - 7 x^3 + 12 x^2 - 28)/x^2:
(x^4 + 3 x^3 - 7 x^3 + 12 x^2 - 28)/x^2
Grouping like terms, x^4 + 3 x^3 - 7 x^3 + 12 x^2 - 28 = x^4 + (3 x^3 - 7 x^3) + 12 x^2 - 28:
(x^4 + (3 x^3 - 7 x^3) + 12 x^2 - 28)/x^2
3 x^3 - 7 x^3 = -4 x^3:
Answer: (x^4 + -4 x^3 + 12 x^2 - 28)/x^2