Solve f7x^4+9x^3-12x^2-9x+7=0

$$f 7 x ^ { 4 } + 9 x ^ { 3 } - 12 x ^ { 2 } - 9 x + 7 = 0$$

Solve for f_7

$$f_{7}=-\frac{9x^{3}-12x^{2}-9x+7}{x^{4}}$$

$$x\neq 0$$

Steps for Solving Linear Equation

Subtract 9x^{3} from both sides. Anything subtracted from zero gives its negation.

$$f_{7}x^{4}-12x^{2}-9x+7=-9x^{3}$$

Add 12x^{2} to both sides.

$$f_{7}x^{4}-9x+7=-9x^{3}+12x^{2}$$

Add 9x to both sides.

$$f_{7}x^{4}+7=-9x^{3}+12x^{2}+9x$$

Subtract 7 from both sides.

$$f_{7}x^{4}=-9x^{3}+12x^{2}+9x-7$$

The equation is in standard form.

$$x^{4}f_{7}=-9x^{3}+12x^{2}+9x-7$$

Divide both sides by x^{4}.

$$\frac{x^{4}f_{7}}{x^{4}}=\frac{-9x^{3}+12x^{2}+9x-7}{x^{4}}$$

Dividing by x^{4} undoes the multiplication by x^{4}.

$$f_{7}=\frac{-9x^{3}+12x^{2}+9x-7}{x^{4}}$$